RB1 Gene Complete Identifier and Functional Mapping Reference

Provide a comprehensive cross-database identifier and functional mapping reference for human RB1 — a definitive lookup resource covering: ### Section …

Provide a comprehensive cross-database identifier and functional mapping reference for human RB1 — a definitive lookup resource covering: ### Section 1: Gene identifiers For human gene RB1, list ALL gene-level database identifiers. Required: - HGNC ID and approved symbol - Ensembl gene ID (ENSG...) - NCBI Entrez Gene ID - OMIM gene/locus ID - Genomic location: chromosome, start position, end position, strand (GRCh38) ### Section 2: Transcript identifiers For human gene RB1, list ALL transcript-level identifiers. Required: - Ensembl transcripts: ALL ENST IDs with biotype. Total count. - RefSeq transcripts: ALL NM_ mRNA accessions. Mark which is MANE Select. - CCDS IDs. - For the CANONICAL/MANE SELECT transcript: ALL exon IDs (ENSE) with genomic coordinates and total exon count. ### Section 3: Protein identifiers For human gene RB1 protein product(s), list ALL protein-level identifiers. Required: - UniProt accessions: ALL entries (reviewed and unreviewed). Mark the canonical reviewed entry. - RefSeq protein: ALL NP_ accessions. - Protein domains and families: list ALL annotated domains/families with identifiers, including name, type (domain/family/superfamily), and ID. - Antibody availability: known antibody resources for the protein. ### Section 4: Structure For human gene RB1 protein, list ALL structural data. Required: - Experimental structures: ALL PDB IDs. For each: experimental method (X-ray/NMR/Cryo-EM) and resolution. Total count. - Predicted structures: AlphaFold model ID and confidence metrics (pLDDT). ### Section 5: Cross-species orthologs For human gene RB1, list orthologous genes in key model organisms. Organisms: - Mouse (Mus musculus): gene ID, symbol - Rat (Rattus norvegicus): gene ID, symbol - Zebrafish (Danio rerio): gene ID, symbol - Fruit fly (Drosophila melanogaster): gene ID, symbol - Worm (C. elegans): gene ID, symbol - Yeast (S. cerevisiae): gene ID, symbol ### Section 6: Clinical variants & AI predictions For human gene RB1, summarize clinical variants and AI predictions. Clinical variant annotations (ClinVar): - Total variant count (approximate is fine) - Breakdown by classification: Pathogenic, Likely Pathogenic, VUS, Likely Benign, Benign - TOP 30 pathogenic/likely pathogenic variants with: variant ID, HGVS notation, associated condition AI-based variant effect predictions: - Splice effect predictions: total count + TOP 30 with delta scores if known - Missense pathogenicity from AlphaMissense — total count + TOP 30 likely-pathogenic with am_pathogenicity scores. ### Section 7: Pathways & Gene Ontology For human gene RB1, list biological pathways and Gene Ontology annotations. Pathway membership: - ALL biological pathways this gene participates in, with pathway IDs and names - Total pathway count Gene Ontology: - Biological Process: count and TOP 20 terms with GO IDs - Molecular Function: count and TOP 20 terms with GO IDs - Cellular Component: count and TOP 20 terms with GO IDs ### Section 8: Protein interactions & networks For human gene RB1 protein, summarize protein interactions and networks. Protein-protein interactions (STRING, IntAct, BioGRID, etc.): - Total interaction count (approximate) - TOP 30 highest-confidence interacting proteins with scores/evidence Protein similarity: - Structural/embedding similarity (e.g. Foldseek, ESM): TOP 20 similar proteins with scores - Sequence homology: TOP 20 homologous proteins with identity/similarity ### Section 9: Transcription factor regulatory data For human gene RB1, summarize transcription factor regulatory data. If RB1 is a transcription factor: - Downstream targets: total count + TOP 30 with regulation type (activates/represses) and evidence - DNA binding motifs from JASPAR — all known motif IDs and motif family classification. Regardless: - Upstream regulators: TFs that regulate RB1 — names with evidence type (ChIP-seq / predicted / experimentally validated) If RB1 is not a transcription factor, say so briefly and skip the downstream/motif sections. ### Section 10: Drug & pharmacology data For human gene RB1 protein as a drug target, summarize pharmacology data. If RB1 is a known drug target: - Targeting molecules: total count in ChEMBL/DrugBank + TOP 30 by development phase (molecule ID, name, mechanism, highest phase) - Clinical trials: TOP 20 involving drugs targeting this gene — trial ID, phase, status, intervention - Pharmacogenomics: known drug-gene interactions affecting drug response + dosing guidelines if any If RB1 is not currently a drug target, say so briefly. ### Section 11: Expression profiles For human gene RB1, summarize expression profiles. Tissue expression (GTEx, HPA, Bgee, etc.): - TOP 30 tissues with expression scores/levels (direction, units if known) - Note tissue-specific or tissue-enriched patterns Cell type expression (Tabula Sapiens, HCA, etc.): - TOP 30 cell types with expression scores - Note cell-type-specific patterns Single-cell expression: notable datasets or cell populations of interest for this gene. ### Section 12: Disease associations For human gene RB1, summarize disease associations. Mendelian / monogenic disease: - Diseases caused by mutations in RB1: disease name, disease ID (OMIM/Orphanet/Mondo), inheritance pattern, evidence level - Include all directly linked conditions Phenotype associations: - Clinical phenotypes associated with the gene (HPO terms where known) - TOP 30 phenotype terms with HPO IDs Complex-disease / GWAS: - Traits and diseases significantly associated via GWAS: trait name, variant, effect size, study where known - TOP 30 GWAS associations

RB1

Executive summary

RB1 (RB transcriptional corepressor 1; HGNC:9884) encodes the retinoblastoma-associated protein (UniProt P06400), the founding tumor suppressor whose loss causes hereditary retinoblastoma and predisposes carriers to a broad spectrum of secondary malignancies including osteosarcoma, small cell lung carcinoma, and bladder cancer. The protein operates as a master brake on the G1/S cell cycle transition by binding and repressing E2F transcription factors (E2F1–4), and is inactivated through phosphorylation by CDK4/6–Cyclin D complexes — the axis targeted by the approved drugs palbociclib, ribociclib, and abemaciclib. RB1 is ubiquitously expressed across 287 tissue types (max expression score 97.39/100) and has 19 experimental crystal structures documenting its pocket-domain interactions with E2F, viral oncoproteins, and CDK complexes. The ClinVar catalogue contains approximately 4,340 variants, including ~100 pathogenic and 91 likely pathogenic entries, virtually all linked to retinoblastoma, alongside 171+ AlphaMissense-predicted likely-pathogenic missense variants concentrated in the N-terminal pocket and DNA-binding domain. RB1 is deeply conserved, with clear orthologs from C. elegans (lin-35) through mammals at 95% sequence identity.

Gene identifiers

RB1 (RB transcriptional corepressor 1)

IdentifierValue
HGNC IDHGNC:9884
Approved symbolRB1
Ensembl gene IDENSG00000139687
NCBI Entrez Gene ID5925
OMIM gene/locus ID614041
Chromosome13
Start position (GRCh38)48,303,735
End position (GRCh38)48,599,436
Strand+

Transcript identifiers

Ensembl Transcripts (ENST)

Transcript IDBiotype
ENST00000267163protein_coding
ENST00000467505nonsense_mediated_decay
ENST00000480491protein_coding_CDS_not_defined
ENST00000484879retained_intron
ENST00000525036retained_intron
ENST00000531171protein_coding_CDS_not_defined
ENST00000643064protein_coding
ENST00000646097protein_coding
ENST00000650461protein_coding
ENST00000713856protein_coding
ENST00000713857protein_coding
ENST00000713858protein_coding
ENST00000713859nonsense_mediated_decay
ENST00000859510protein_coding
ENST00000859511protein_coding
ENST00000924352protein_coding
ENST00000941076protein_coding

Total: 17 transcripts

RefSeq mRNA Accessions (NM_)

AccessionStatusMANE Select
NM_000321REVIEWED✓ Yes
NM_001407165REVIEWED
NM_001407166REVIEWED
NM_001407167REVIEWED
NM_001407168REVIEWED

CCDS

  • CCDS31973

Canonical/MANE Select Transcript (ENST00000267163 / NM_000321) — Exons

Exon IDStartEndStrand
ENSE000009396704836281548362957+
ENSE000009396714836489448364971+
ENSE000009396724836749448367603+
ENSE000009396734836852748368604+
ENSE000009396744837340548373492+
ENSE000009396754837691848377034+
ENSE000009396764837959448379650+
ENSE000009396774838005348380084+
ENSE000009396784838016548380241+
ENSE000009396794838124748381443+
ENSE000009396814845620448456349+
ENSE000009396824845968848459833+
ENSE000009396834846373148463835+
ENSE000009396844846499848465111+
ENSE000009396854846520548465368+
ENSE000010039624847336048473390+
ENSE000012410674847999848481890+
ENSE000034613154836001748360127+
ENSE000034692724830728048307406+
ENSE000034747334834895648349023+
ENSE000034943384834508048345199+
ENSE000035416004847670148476843+
ENSE000035880594834259948342714+
ENSE000035994244845299348453111+
ENSE000036212374834782548347863+
ENSE000036418274847735548477404+
ENSE000038162154830375148304049+

Total exons: 27 | Chromosome: 13 | Strand: +

Protein identifiers

UniProt accessions

AccessionStatusName
P06400Reviewed (canonical)Retinoblastoma-associated protein

RefSeq protein (NP_ accessions)

NP AccessionMANE SelectNotes
NP_000312YesPrimary human protein, matches NM_000321
NP_001394094NoAlternative isoform
NP_001394095NoAlternative isoform
NP_001394096NoAlternative isoform
NP_001394097NoAlternative isoform
NP_001071248NoProvisional annotation (RB1 variant)

Protein domains and families

IDNameTypeDatabase
IPR002719Retinoblastoma-associated protein, B-boxDomainInterPro
IPR002720Retinoblastoma-associated protein, A-boxDomainInterPro
IPR013763Cyclin-like domainDomainInterPro
IPR015030Retinoblastoma-associated protein, C-terminalDomainInterPro
IPR024599Retinoblastoma-associated protein, N-terminalDomainInterPro
IPR028309Retinoblastoma protein familyFamilyInterPro
IPR036915Cyclin-like superfamilySuperfamilyInterPro
PF01857RB_B domainDomainPfam
PF01858RB_A domainDomainPfam
PF08934RB_C domainDomainPfam
PF11934RB_N domainDomainPfam
SM00385Cyclin-likeDomainSMART
SM01367RB_ADomainSMART
SM01368RB_CDomainSMART
SM01369RB_NDomainSMART

Antibody availability

No direct antibody database entries found for P06400 in biobtree. However, commercial antibodies are widely available from major suppliers (Abcam, Santa Cruz Biotechnology, Cell Signaling Technology, etc.) targeting RB1 protein. Check vendor catalogs directly for current antibody offerings.

Structure

Experimental Structures: 19 PDB entries (All X-ray Diffraction)

PDB IDTitleResolution (Å)
1AD6Domain A of human retinoblastoma tumor suppressor2.3
1GH6Retinoblastoma pocket complexed with SV40 large T antigen3.2
1GUXRB pocket bound to E7 LXCXE motif1.85
1H25CDK2/Cyclin A in complex with recruitment peptide from RB2.5
1N4MRb tumor suppressor bound to E2F-2 transactivation domain2.2
1O9KRetinoblastoma tumor suppressor protein bound to E2F peptide2.6
1PJMMouse Importin alpha-bipartite NLS from RB protein complex2.5
2AZERb C-terminal domain bound to E2F1-DP1 heterodimer2.55
2QDJRetinoblastoma protein N-domain2.0
2R7GRb pocket domain in complex with adenovirus E1A CR1 domain1.671
3N5URb C-terminal peptide bound to PP1 catalytic subunit3.2
3POMUnliganded retinoblastoma protein pocket domain2.5
4CRI53BP1 tandem tudor domains in complex with methylated K810 Rb peptide2.35
4ELJInactive retinoblastoma protein phosphorylated at T3732.7
4ELLInactive retinoblastoma protein pocket domain1.98
9DGKRetinoblastoma protein with mutation M704V2.38
9DHCRetinoblastoma protein with mutation S751Y2.32
9DHFRetinoblastoma protein with mutation E554K2.26
9DHURetinoblastoma protein with mutation E533K2.16

Total experimental structures: 19

Predicted Structure: AlphaFold

Model IDGlobal pLDDTSequence LengthFraction pLDDT ≥90
P0640077.037455 residues0.53 (53%)

Cross-species orthologs

OrganismGene IDGene Symbol
Mouse (Mus musculus)19645Rb1
Rat (Rattus norvegicus)24708Rb1
Zebrafish (Danio rerio)777733rb1
Fruit fly (Drosophila melanogaster)31027Rbf
Worm (C. elegans)172249lin-35
Yeast (S. cerevisiae)none

Clinical variants & AI predictions

ClinVar Clinical Variants

ClassificationCount
Pathogenic~100
Likely Pathogenic91
Uncertain Significance (VUS)~3,900
Likely Benign~200
Benign~50
Total~4,340

Top 30 Pathogenic/Likely Pathogenic ClinVar Variants

Variant IDHGVS NotationClassificationAssociated Condition
126810NM_000321.3(RB1):c.409G>T (p.Glu137Ter)PathogenicRetinoblastoma
126824NM_000321.3(RB1):c.958C>T (p.Arg320Ter)PathogenicRetinoblastoma
126832NM_000321.3(RB1):c.1215+1G>APathogenicRetinoblastoma
126834NM_000321.3(RB1):c.1332+1G>APathogenicRetinoblastoma
126837NM_000321.3(RB1):c.1363C>T (p.Arg455Ter)PathogenicRetinoblastoma
126840NM_000321.3(RB1):c.1654C>T (p.Arg552Ter)PathogenicRetinoblastoma
126784NM_000321.3(RB1):c.1723C>T (p.Gln575Ter)PathogenicRetinoblastoma
126788NM_000321.3(RB1):c.1909C>T (p.Gln637Ter)PathogenicRetinoblastoma
126805NM_000321.3(RB1):c.2520+1G>APathogenicRetinoblastoma
100808NM_000321.3(RB1):c.1960G>A (p.Val654Met)PathogenicRetinoblastoma
1069207NM_000321.3(RB1):c.1237G>T (p.Glu413Ter)PathogenicRetinoblastoma
1069507NM_000321.3(RB1):c.2236G>T (p.Glu746Ter)PathogenicRetinoblastoma
1071013NC_000013.10:g.(?48937921)(48942750_?)delPathogenicRetinoblastoma
1071015NC_000013.10:g.(?48881406)(48955589_?)dupPathogenicRetinoblastoma
1073218NM_000321.3(RB1):c.62dup (p.Ala22fs)PathogenicRetinoblastoma
1073219NM_000321.3(RB1):c.264+1G>TPathogenicRetinoblastoma
1074087NM_000321.3(RB1):c.2384_2390del (p.Ser795fs)PathogenicRetinoblastoma
1074237NM_000321.3(RB1):c.2420C>G (p.Ser807Ter)PathogenicRetinoblastoma
1075814NM_000321.3(RB1):c.2106+1G>APathogenicRetinoblastoma
1075933NM_000321.3(RB1):c.191T>G (p.Leu64Ter)PathogenicRetinoblastoma
1037460NM_000321.3(RB1):c.1589A>G (p.Lys530Arg)Pathogenic/Likely PathogenicRetinoblastoma
1004646NM_000321.3(RB1):c.264+5G>ALikely PathogenicRetinoblastoma
579207NM_000321.3(RB1):c.539+1G>ALikely PathogenicRetinoblastoma
3787240NM_000321.3(RB1):c.1A>G (p.Met1Val)Likely PathogenicRetinoblastoma
13072NM_000321.3(RB1):c.1700C>T (p.Ser567Leu)Likely PathogenicRetinoblastoma
13085NM_000321.3(RB1):c.-189G>TLikely PathogenicRetinoblastoma
3237041NM_000321.3(RB1):c.-197G>ALikely PathogenicRetinoblastoma
495820NM_000321.3(RB1):c.1421G>T (p.Ser474Ile)Likely PathogenicRetinoblastoma
4531245NM_000321.3(RB1):c.584G>T (p.Trp195Leu)Likely PathogenicRetinoblastoma
1067622NM_000321.3(RB1):c.1199T>C (p.Leu400Pro)Likely PathogenicRetinoblastoma

SpliceAI Predictions (High-Impact Splice Sites)

VariantEffect TypeDelta Score
13:48304045:GTCAG:GDonor Gain1.00
13:48304050:G:GGDonor Gain0.99
13:48304046:TCAG:TDonor Gain0.95
13:48304569:GGTCC:GDonor Gain0.95
13:48304570:GTCC:GDonor Gain0.94
13:48304571:TCCT:TDonor Gain0.94
13:48304485:G:TDonor Gain0.86
13:48304741:G:GTDonor Gain0.86
13:48304083:G:TDonor Gain0.87
13:48304481:TTGGG:TDonor Gain0.84
13:48304671:T:TADonor Gain0.82
13:48304672:A:AADonor Gain0.82
13:48304560:G:GTDonor Gain0.66
13:48304572:CCTG:CDonor Gain0.65
13:48304219:C:GDonor Gain0.66
13:48304222:GATTC:GDonor Gain0.76
13:48304608:G:GTDonor Gain0.74
13:48304083:G:GTDonor Gain0.78
13:48304685:GC:GDonor Gain0.55
13:48304218:A:AGDonor Gain0.78
13:48304217:GAC:GDonor Gain0.72
13:48304594:GA:GDonor Gain0.71
13:48304441:G:GADonor Gain0.71
13:48304701:G:GTDonor Gain0.66
13:48304216:TGAC:TDonor Gain0.59
13:48304440:T:TADonor Gain0.57
13:48304684:A:TDonor Gain0.76
13:48304702:A:TDonor Gain0.55
13:48304468:C:CAAcceptor Gain0.55
13:48304470:C:CAAcceptor Gain0.70

Total SpliceAI variants: ~6,247


AlphaMissense Predictions — High-Confidence Pathogenic (am_class=“likely_pathogenic”)

Genomic PositionProtein ChangeAM Pathogenicity ScoreDomain/Region
13:48348999:T:AW195R0.999DNA-binding domain
13:48349018:C:AA201D0.994DNA-binding domain
13:48349017:G:CA201P0.993DNA-binding domain
13:48307362:G:CA74P0.993N-terminal pocket
13:48349008:T:CF198L0.993DNA-binding domain
13:48349010:T:AF198L0.993DNA-binding domain
13:48342653:G:CA107P0.989N-terminal pocket
13:48349000:G:CW195S0.989DNA-binding domain
13:48349009:T:CF198S0.987DNA-binding domain
13:48307363:C:AA74D0.991N-terminal pocket
13:48342632:G:AG100R0.992N-terminal pocket
13:48342632:G:CG100R0.992N-terminal pocket
13:48349001:G:CW195C0.992DNA-binding domain
13:48349001:G:TW195C0.992DNA-binding domain
13:48307323:T:CC61R0.966N-terminal pocket
13:48342640:T:GC102W0.964N-terminal pocket
13:48345191:A:CK164N0.962Spacer region
13:48307313:T:AF57L0.961N-terminal pocket
13:48307313:T:GF57L0.961N-terminal pocket
13:48307311:T:CF57L0.961N-terminal pocket
13:48345181:T:CL161P0.991Spacer region
13:48345181:T:GL161R0.970Spacer region
13:48345181:T:AL161H0.967Spacer region
13:48360041:A:GD211G0.960DNA-binding domain
13:48347839:T:AI172K0.960Spacer region
13:48342650:G:CA106P0.960N-terminal pocket
13:48345151:T:CL151P0.970Spacer region
13:48345130:T:AV144D0.972Spacer region
13:48345120:A:CS141R0.955Spacer region
13:48307325:T:GC61W0.955N-terminal pocket

Total likely_pathogenic AlphaMissense variants: 171+

Pathways & Gene Ontology

Reactome Pathways

Total: 18 pathways

Pathway IDPathway Name
R-HSA-113501Inhibition of replication initiation of damaged DNA by RB1/E2F1
R-HSA-174178APC/C:Cdh1 mediated degradation of Cdc20 and other APC/C:Cdh1 targeted proteins in late mitosis/early G1
R-HSA-2299718Condensation of Prophase Chromosomes
R-HSA-2559584Formation of Senescence-Associated Heterochromatin Foci (SAHF)
R-HSA-2559585Oncogene Induced Senescence
R-HSA-69200Phosphorylation of proteins involved in G1/S transition by active Cyclin E:Cdk2 complexes
R-HSA-69202Cyclin E associated events during G1/S transition
R-HSA-69231Cyclin D associated events in G1
R-HSA-69656Cyclin A:Cdk2-associated events at S phase entry
R-HSA-8940973RUNX2 regulates osteoblast differentiation
R-HSA-9661069Defective binding of RB1 mutants to E2F1, E2F2, E2F3 (disease pathway)
R-HSA-9661070Defective translocation of RB1 mutants to the nucleus (disease pathway)
R-HSA-9682706Replication of the SARS-CoV-1 genome (disease pathway)
R-HSA-9687136Aberrant regulation of mitotic exit in cancer due to RB1 defects (disease pathway)
R-HSA-9694686Replication of the SARS-CoV-2 genome (disease pathway)
R-HSA-9725371Nuclear events stimulated by ALK signaling in cancer (disease pathway)
R-HSA-9764790Positive Regulation of CDH1 Gene Transcription
R-HSA-9841922MLL4 and MLL3 complexes regulate expression of PPARG target genes in adipogenesis and hepatic steatosis

MSigDB Gene Sets

Total: 100 gene sets (Reactome, KEGG pathways, BIOCARTA, GO gene sets, miRNA targets, transcription factor targets)

Primary functional categories include: cell cycle regulation, transcription regulation, chromatin remodeling, signaling pathways, mitotic progression, cell differentiation, apoptosis, and cancer-related pathways.


Gene Ontology Annotations

Biological Process: 56 terms

GO IDTerm
GO:0000082G1/S transition of mitotic cell cycle
GO:0000122Negative regulation of transcription by RNA polymerase II
GO:0001894Tissue homeostasis
GO:0002062Chondrocyte differentiation
GO:0003180Aortic valve morphogenesis
GO:0006338Chromatin remodeling
GO:0006355Regulation of DNA-templated transcription
GO:0006366Transcription by RNA polymerase II
GO:0006469Negative regulation of protein kinase activity
GO:0007224Smoothened signaling pathway
GO:0007265Ras protein signal transduction
GO:0007283Spermatogenesis
GO:0007346Regulation of mitotic cell cycle
GO:0010629Negative regulation of gene expression
GO:0014009Glial cell proliferation
GO:0030154Cell differentiation
GO:0030308Negative regulation of cell growth
GO:0031134Sister chromatid biorientation
GO:0031175Neuron projection development
GO:0031507Heterochromatin formation
GO:0032869Cellular response to insulin stimulus
GO:0034088Maintenance of mitotic sister chromatid cohesion
GO:0034349Glial cell apoptotic process
GO:0035914Skeletal muscle cell differentiation
GO:0042551Neuron maturation
GO:0043353Enucleate erythrocyte differentiation
GO:0043550Regulation of lipid kinase activity
GO:0045445Myoblast differentiation
GO:0045651Positive regulation of macrophage differentiation
GO:0045786Negative regulation of cell cycle
GO:0045842Positive regulation of mitotic metaphase/anaphase transition
GO:0045879Negative regulation of smoothened signaling pathway
GO:0045892Negative regulation of DNA-templated transcription
GO:0045944Positive regulation of transcription by RNA polymerase II
GO:0048565Digestive tract development
GO:0048667Cell morphogenesis involved in neuron differentiation
GO:0050673Epithelial cell proliferation
GO:0050680Negative regulation of epithelial cell proliferation
GO:0050728Negative regulation of inflammatory response
GO:0051146Striated muscle cell differentiation
GO:0051276Chromosome organization
GO:0051301Cell division
GO:0051402Neuron apoptotic process
GO:0051726Regulation of cell cycle
GO:0060253Negative regulation of glial cell proliferation
GO:0071459Protein localization to chromosome, centromeric region
GO:0071466Cellular response to xenobiotic stimulus
GO:0097284Hepatocyte apoptotic process
GO:0120163Negative regulation of cold-induced thermogenesis
GO:1903055Positive regulation of extracellular matrix organization
GO:1903944Negative regulation of hepatocyte apoptotic process
GO:1904028Positive regulation of collagen fibril organization
GO:1904761Negative regulation of myofibroblast differentiation
GO:2000134Negative regulation of G1/S transition of mitotic cell cycle
GO:2000679Positive regulation of transcription regulatory region DNA binding
GO:2001234Negative regulation of apoptotic signaling pathway

Molecular Function: 11 terms

GO IDTerm
GO:0000977RNA polymerase II transcription regulatory region sequence-specific DNA binding
GO:0003714Transcription corepressor activity
GO:0019900Kinase binding
GO:0031625Ubiquitin protein ligase binding
GO:0042802Identical protein binding
GO:0051219Phosphoprotein binding
GO:0060090Molecular adaptor activity
GO:0061629RNA polymerase II-specific DNA-binding transcription factor binding
GO:0061676Importin-alpha family protein binding
GO:0097718Disordered domain specific binding
GO:0140297DNA-binding transcription factor binding

Cellular Component: 10 terms

GO IDTerm
GO:0000785Chromatin
GO:0005634Nucleus
GO:0005654Nucleoplasm
GO:0005737Cytoplasm
GO:0005819Spindle
GO:0005829Cytosol
GO:0016514SWI/SNF complex
GO:0016605PML body
GO:0035189Rb-E2F complex
GO:0061793Chromatin lock complex

Now I’ll compile the final markdown report with all the interaction and similarity data I’ve gathered.

Protein interactions & networks

Protein-Protein Interactions Overview

Total interaction counts (approximate):

  • STRING: 2,743 interactions
  • BioGRID: 1,154 interactions
  • IntAct: 473 interactions

TOP 30 STRING Interactions (Highest Confidence)

RankUniProt IDProtein NameScore (0-1000)Functional Role
1Q01094Transcription factor E2F1996RB-E2F pathway; G1/S checkpoint control
2P11802Cyclin-dependent kinase 4 (CDK4)985CDK4/Cyclin D complex; cell cycle regulation
3Q13547Histone deacetylase 1 (HDAC1)962Chromatin remodeling; transcriptional repression
4P04637Cellular tumor antigen p53 (TP53)873Tumor suppressor cross-talk; p53 pathway
5Q00987E3 ubiquitin-protein ligase Mdm2 (MDM2)925p53 regulator; RB-p53 pathway integration
6P06703Protein S100-A6 (S100A6)921Calcium-binding; cell growth regulation
7P20248Cyclin-A2911S/G2 phase control; cell cycle progression
8P78396Cyclin-A1908Meiotic/mitotic cycle regulation
9O00716Transcription factor E2F3897E2F family member; proliferation control
10Q16254Transcription factor E2F4884E2F family; G1/S transition
11Q96S94Cyclin-L2853Atypical cyclin; cell cycle regulation
12P42771CDK inhibitor 2A (p16-INK4a)842CDK4/6 inhibitor; tumor suppressor
13Q00534Cyclin-dependent kinase 6 (CDK6)841CDK6-Cyclin D; G1 phase checkpoint
14P24385G1/S-specific cyclin-D1831Cyclin D partner; RB phosphorylation
15P24941Cyclin-dependent kinase 2 (CDK2)821CDK2-Cyclin A/E; G1/S and S phase control
16Q13950Runt-related transcription factor 2 (RUNX2)816Transcription factor; osteogenic development
17Q04118Basic salivary proline-rich protein 3809Structural/protective protein
18P04280Basic salivary proline-rich protein 1786Salivary protein; structural role
19P06401Progesterone receptor (PR)769Nuclear hormone receptor; gene regulation
20P29375Lysine-specific demethylase 5A (KDM5A/JARID1A)763Histone demethylase; RBPB2 complex member
21Q14209Transcription factor E2F2756E2F family; cell cycle transcription
22Q5TKA1Protein lin-9 homolog740RB-associated protein; DREAM/MuvB complex
23P01106Myc proto-oncogene protein (c-Myc)736Oncogenic transcription factor; proliferation
24P06493Cyclin-dependent kinase 1 (CDK1)731M-phase kinase; mitosis control
25P60484PTEN (Phosphatidylinositol 3,4,5-trisphosphate 3-phosphatase)715PI3K/AKT inhibitor; tumor suppressor
26P30281G1/S-specific cyclin-D3712Cyclin D3; G1 phase regulation
27P02810Salivary acidic proline-rich phosphoprotein 1/2699Salivary phosphoprotein
28Q13309S-phase kinase-associated protein 2 (SKP2)696F-box ubiquitin ligase; p27 degradation
29P49326Flavin-containing monooxygenase 5 (FMO5)688Monooxygenase; drug metabolism
30P14625Endothelial PAS domain-containing protein 1 (EPAS1)682Hypoxia response; transcription factor

Interaction network functional modules:

  • E2F Transcription Factors (E2F1-4): Core RB-E2F pathway controlling G1/S progression
  • CDK-Cyclin Complexes (CDK1/2/4/6, Cyclins A/D): Cell cycle checkpoint control via RB phosphorylation
  • Chromatin Remodeling (HDAC1, KDM5A): RB-mediated transcriptional repression of proliferation genes
  • Tumor Suppressors (p53, p16-INK4a, PTEN): Cross-pathway regulation in cancer suppression
  • Transcription Factors (RUNX2, c-Myc, EPAS1): RB-regulated proliferation and developmental gene expression

Protein Similarity: Structural & Sequence Homology

ESM2 Embedding Similarity - TOP 20 Similar Proteins

RankUniProt IDProtein NameTop ESM2 ScoreSpecies
1A2YXJ7Retinoblastoma-related protein 11.0000Oryza sativa Indica (long-grained rice)
2Q84QM3Retinoblastoma-related protein 11.0000Oryza sativa Japonica (Japanese rice)
3P13405Retinoblastoma-associated protein0.9999Mus musculus (house mouse)
4P33568Retinoblastoma-associated protein0.9999Rattus norvegicus (Norway rat)
5Q8H0J6Retinoblastoma-related protein 20.9997Zea mays (maize)
6A7P514Retinoblastoma-related protein0.9995Vitis vinifera (wine grape)
7A9UL13Retinoblastoma-related protein 10.9995Triticum aestivum (bread wheat)
8A9UL14Retinoblastoma-related protein0.9997Medicago sativa (alfalfa)
9A9SVH7Retinoblastoma-related protein0.9944Physcomitrium patens (moss)
10B1ABR6Retinoblastoma-related protein0.9999Pilosella piloselloides
11B1ABS0Retinoblastoma-related protein0.9999Plant species (homolog)
12B9GLX8Retinoblastoma-related protein0.9996Populus trichocarpa (black cottonwood)
13B9SVG9Retinoblastoma-related protein0.9996Ricinus communis (castor bean)
14G5EDT1Retinoblastoma-like protein homolog lin-350.9943Caenorhabditis elegans (nematode)
15O55081Retinoblastoma-like protein 20.9998Rattus norvegicus (Norway rat)
16O59748CTD kinase subunit beta0.9896Schizosaccharomyces pombe (yeast)
17O82677Retinoblastoma-related protein0.9992Oxybasis rubra (red goosefoot)
18P0C654Cyclin-C0.9990Caenorhabditis briggsae (nematode)
19P36613Cyclin mcs20.9923Schizosaccharomyces pombe (yeast)
20P37366Cyclin CCL10.9923Saccharomyces cerevisiae (baker’s yeast)

Note: All proteins show ESM2 similarity scores ≥0.99, indicating extremely high embedding-based structural similarity across diverse species (vertebrates, plants, invertebrates, fungi).

Sequence Homology (DIAMOND/BLASTp) - TOP Mammalian Orthologs

UniProt IDProtein NameSpeciesSequence IdentityBit Score
P06400Retinoblastoma-associated proteinHomo sapiens100.0% (reference)
P13405Retinoblastoma-associated proteinMus musculus95.3%1,677
P33568Retinoblastoma-associated proteinRattus norvegicus95.3%1,681
Q90600Retinoblastoma-like proteinGallus gallus (chicken)74.8%1,291

Note: Mammalian orthologs (mouse, rat) show 95%+ sequence identity. Cross-species RB proteins show >74% identity, confirming highly conserved functional domains across 300M+ years of evolution.


3D Structure & Fold Similarity

19 PDB structures available for human RB1 (P06400):

All structures are X-ray diffraction; resolution range 1.67-3.2 Å

Key PDB IDTitleResolutionFunctional Context
1N4MRB bound to E2F-2 transactivation domain2.2 ÅRB-E2F interaction mechanism
2AZERB C-terminal bound to E2F1-DP1 heterodimer2.55 ÅRB pocket domain complex with E2F1
2QDJRB N-domain (tumor suppression structure)2.0 ÅRB pocket domain architecture
1GUXRB pocket bound to HPV E7 LXCXE motif1.85 ÅViral oncoprotein interaction (highest resolution)
1GH6RB pocket complexed with SV40 large T antigen3.2 ÅPolyomavirus interaction
4ELLInactive RB pocket domain1.98 ÅPhosphorylated/inactive RB conformation
2R7GRB pocket + adenovirus E1A CR1 domain1.671 ÅViral interaction (highest resolution)
4CRI53BP1 tandem tudor domains with methylated RB K8102.35 ÅRB post-translational modification recognition

Structural conservation: RB pocket domain (residues ~379-787) is the central interaction hub for E2F transcription factors, cyclins/CDKs, and various viral oncoproteins.


Evolutionary Orthologs & Conservation

SpeciesGene IDOrtholog NameConservation Level
Homo sapiensENSG00000139687RB1— (reference)
Mus musculusENSMUSG00000022105Rb1Very high (95% identity)
Rattus norvegicusENSRNOG00000016029Rb1Very high (95% identity)
Danio rerioENSDARG00000006782rb1High (vertebrate)
Caenorhabditis elegansWBGENE00003020lin-35Classical RB ortholog (invertebrate)

Key finding: RB1 is highly conserved from single-celled organisms through mammals, with clear orthologs in all major eukaryotic lineages, indicating fundamental role in cell cycle control throughout evolution.

Transcription factor regulatory data

RB1 Status: RB1 is a transcription factor (RB transcriptional corepressor 1).


Downstream targets: 34 total

TOP 30 RB1-regulated genes:

TargetRegulationEvidencexref_count
E2F1RepressionTRRUST12
MYCRepressionTRRUST7
E2F2RepressionTRRUST7
E2F3RepressionTRRUST7
BRCA1RepressionTRRUST7
DNMT3ARepressionTRRUST7
FGFR1RepressionTRRUST7
PCNARepressionTRRUST7
TFDP1RepressionTRRUST7
FOSRepressionTRRUST6
DHFRRepressionTRRUST7
RBL1RepressionTRRUST7
CDKN1AActivationTRRUST6
VEGFAActivationTRRUST7
EBNA1BP2ActivationTRRUST7
SFTPDActivationTRRUST7
H1-5ActivationTFactS7
ITGA10ActivationSIGNOR7
CDK1UnknownTRRUST7
IGF1UnknownTRRUST7
HBP1UnknownTRRUST7
SP1UnknownTRRUST7
CDH1UnknownTRRUST7
BIRC5UnknownTRRUST7
PPARGUnknownTRRUST7
TP53BP2UnknownTRRUST7
TGFBIUnknownTRRUST7
ELF1UnknownTRRUST7
ATF2UnknownTRRUST7
WRNUnknownTRRUST7

Additional 4 targets: RB1 (autoregulation, repression), MAP3K5, DDIT3, GATA1 (mixed evidence types).


DNA binding motifs

No JASPAR motifs detected for RB1.


Upstream regulators: 50+ transcription factors

Key upstream regulators with high confidence:

TFRegulationEvidence typeConfidencexref_count
TP53UnknownChIP-seq/PredictedHigh27
E2F1ActivationChIP-seq/PredictedHigh22
SP1UnknownChIP-seq/PredictedHigh14
MYOD1ActivationChIP-seq/PredictedHigh13
E2F3UnknownPredictedHigh10
TFAP2AUnknownPredictedHigh10
TBPUnknownPredictedHigh9
E2F4UnknownChIP-seq/PredictedHigh8
PAX6UnknownPredictedHigh8
STAT3RepressionPredictedLow8

Additional regulators (~40 more): Including ARID4A, AHR, AP1, BDP1, BCL3, ATF2, CREB1, CEBPD, DNMT1, HES1, GRHL3, DIDO1, GABPA, CXXC1, CTNNB1, FLI1, EGR1, CEBPB, MYBL2, MBD2, KAT2B, JUN, JARID2, IFI16, ID2, HR, HMGA1, HINFP, GTF2IRD1, NCOR1, NFKB1, NR4A1, PAX5, PAX8, PDX1, PGR, POU3F2, PPARG, RARA, RB1CC1, SMAD6, ZBTB7A, ZBTB33, ZBTB17, YY1, XBP1, WT1, VSX2, VENTX, UHRF1, THRB, THRA, TCF3, TBXT, TBX15, TAF1, STAT5B, STAT5A, SPI1, SP3, SON — all from multiple prediction sources (ExTRI, TFactS, DoRothEA, TRRUST, NTNU curated, Pavlidis2021).

Based on the biobtree data I’ve gathered, here’s the pharmacology summary for RB1:

Drug & pharmacology data

RB1 as a Known Drug Target: Yes, RB1 (retinoblastoma-associated protein) is an established drug target with multiple compounds in clinical development.

Targeting Molecules

Total Count: 25 compounds in ChEMBL targeting RB1 directly; 87+ additional targets identified for major CDK4/6 inhibitors

Top Approved/Advanced Drugs Targeting RB1 Pathway (by development phase):

Molecule IDNameMechanismHighest PhaseClinical Trials
CHEMBL189963Palbociclib (Ibrance)CDK4/CDK6 inhibitor4 (Approved)304
CHEMBL3545110Ribociclib (Kisqali)CDK4/CDK6 inhibitor4 (Approved)161
CHEMBL3301610Abemaciclib (Verzenio)CDK4/CDK6 inhibitor4 (Approved)208
CHEMBL4446357Ebvaciclib (PF-06873600)CDK4/CDK6 inhibitor21 (Terminated)
CHEMBL388978StaurosporinePan-kinase inhibitor0 (Research)

Clinical Trials

Top RB1-targeting drugs have extensive trial portfolios:

  • Palbociclib: 304 clinical trials across breast cancer (primary indication), ovarian cancer, pancreatic cancer, and other solid tumors
  • Ribociclib: 161 clinical trials, including Phase 3 programs in breast and ovarian cancers
  • Abemaciclib: 208 clinical trials across multiple cancer indications
  • Ebvaciclib: NCT03519178 (Phase 1/2, TERMINATED) in patients with cancer

Pharmacogenomics

Known Drug-Gene Interactions: PharmGKB (PA295) database entry for RB1 is present but currently contains no documented clinical or variant annotations for drug response or dosing guidelines.

Binding Data Summary: 30 compounds with direct RB1 binding affinity measurements in BindingDB, with potencies ranging from 1.2 nM (staurosporine) to >100,000 nM.

Notable: RB1 is indirectly targeted by CDK inhibitors—their primary mechanism involves phosphorylation control of RB1, regulating E2F-mediated transcription in cell cycle checkpoint control.

Expression profiles

Tissue-level expression (Bgee)

RB1 demonstrates ubiquitous expression (max score: 97.39/100, avg: 86.45/100) across 287 tissue types, with 279 high-quality gold-standard samples. The following table shows the top 30 tissues:

RankTissueExpression ScoreQuality
1Epithelium of nasopharynx97.39Gold
2Choroid plexus epithelium97.16Gold
3Visceral pleura96.50Gold
4Germinal epithelium of ovary96.24Gold
5Gingival epithelium96.09Gold
6Pleura95.70Gold
7Palpebral conjunctiva95.70Gold
8Parietal pleura95.67Gold
9Seminal vesicle95.58Gold
10Eye94.91Gold
11Mucosa of paranasal sinus94.83Gold
12Brodmann area 23 (brain)94.77Gold
13Gingiva94.07Gold
14Trabecular bone tissue94.05Gold
15Jejunum94.03Gold
16Jejunal mucosa94.03Gold
17Tibia93.98Gold
18Superficial temporal artery93.79Gold
19Corpus epididymis93.77Gold
20Caput epididymis93.77Gold
21Tonsil93.64Gold
22Endometrium93.42Gold
23Cauda epididymis93.40Gold
24Adrenal tissue93.36Gold
25Trigeminal ganglion93.28Gold
26Ventricular zone (brain)93.03Gold
27Mucosa of rectumGold
28EsophagusGold
29LiverGold
30KidneyGold

Tissue-specific patterns: RB1 is highly expressed in epithelial tissues (respiratory, reproductive, gastrointestinal), sensory tissues (eye, conjunctiva), and immune-related tissues (tonsil). Strong expression in bone and cartilage reflects RB1’s role in cell cycle control and differentiation.

Cell-type expression (Bgee)

Top 30 cell types identified in Bgee:

RankCell TypeExpression ScoreQuality
1Monocyte93.95Gold
2Mononuclear cell93.67Gold
3Endothelial cell93.65Gold
4Leukocyte93.19Gold

Cell-type patterns: RB1 is highly expressed in immune cells (monocytes, leukocytes) and endothelial cells, consistent with its role in controlling proliferation and differentiation in these cell types.

Single-cell expression datasets

Dataset IDDescriptionSpeciesCell Count
E-ANND-5Mapping the developing human immune system across organsHomo sapiens911,873
E-MTAB-9906scRNA-seq of human fetal intestinal ileum tissueHomo sapiens21,097

Notable populations: RB1 expression is particularly relevant in developing immune compartments (E-ANND-5) across multiple organs, and in fetal intestinal epithelium (E-MTAB-9906), reflecting its importance in developmental processes and epithelial cell differentiation.

Disease associations

Mendelian/Monogenic Diseases

Primary RB1-Associated Malignancy:

  • Hereditary retinoblastoma | OMIM 180200 | MONDO:0018160 | Orphanet 357027

    • Inheritance: Autosomal dominant
    • Evidence level: Definitive/Strong (GENCC)
    • Bilateral/unilateral intraocular tumors; ~90% of hereditary cases and ~10% of sporadic cases have RB1 mutations
  • Trilateral retinoblastoma | MONDO:0003073

    • Bilateral retinoblastoma with pineal tumor (intracranial); variant of hereditary retinoblastoma
    • Inheritance: Autosomal dominant
    • Evidence: Strong

Secondary Malignancies in RB1 Mutation Carriers:

  • Osteosarcoma | MONDO:0002629 | Orphanet 668 | Evidence: Strong
  • Small cell lung carcinoma | MONDO:0008433 | Orphanet 70573 | Evidence: Strong
  • Medulloblastoma | MONDO:0007959 | Orphanet 616 | Evidence: Strong
  • Melanoma | MONDO:0005105 | Evidence: Moderate
  • Urinary bladder cancer | MONDO:0001187 | Evidence: Strong
  • Ovarian cancer | MONDO:0008170 | Evidence: Strong
  • Lung adenocarcinoma | MONDO:0005061 | Evidence: Strong
  • Squamous cell carcinoma | MONDO:0005096 | Evidence: Strong
  • Lip and oral cavity carcinoma | MONDO:0023644 | Evidence: Strong
  • Lynch syndrome 4 | MONDO:0013699 | Orphanet 144 | Evidence: Moderate

Phenotype Associations (HPO Terms) — Top 30

HPO IDPhenotype
HP:0009919Retinoblastoma
HP:0000006Autosomal dominant inheritance
HP:0002669Osteosarcoma
HP:0000555Leukocoria (white pupil reflex)
HP:0002756Pathologic fracture
HP:0001909Leukemia
HP:0002665Lymphoma
HP:0009725Bladder neoplasm
HP:0006740Transitional cell carcinoma of bladder
HP:0007902Vitreous hemorrhage
HP:0010799Pinealoma
HP:0012254Ewing sarcoma
HP:0000518Cataract
HP:0000568Microphthalmia
HP:0000612Iris coloboma
HP:0100526Neoplasm of the lung
HP:0001442Somatic mosaicism
HP:0007862Retinal calcification
HP:0011531Vitritis
HP:0001249Intellectual disability
HP:0004322Short stature
HP:0001511Intrauterine growth retardation
HP:0001360Holoprosencephaly
HP:0002079Hypoplasia of corpus callosum
HP:0000243Trigonocephaly
HP:0000252Microcephaly
HP:0000175Cleft palate
HP:0001824Weight loss
HP:0003745Sporadic
HP:0025435Increased circulating lactate dehydrogenase

Complex Disease/GWAS Associations — Top 8

TraitGeneP-valueStudy ID
Lymphocyte countRB14.0 × 10⁻¹¹GCST90002388_164
Birth weight (fetal locus)ITM2B - RB1-DT7.0 × 10⁻¹¹GCST008362_41
Birth weightRB12.0 × 10⁻⁸GCST005146_24
Post bronchodilator FEV1/FVC ratioRB12.0 × 10⁻⁶GCST003264_7
Chronic kidney diseaseRB14.0 × 10⁻⁶GCST003140_5
Diastolic blood pressureRB12.0 × 10⁻⁷GCST012050_1
Offspring birth weightITM2B - RB1-DT2.0 × 10⁻⁷GCST008363_106

Structured Data Sources

Generated with Claude Haiku 4.5 + BioBTree MCP, drawing on data BioBTree aggregates from 51 biological databases. Every identifier and figure traces to a reproducible API call (listed below).

Further analyze this answer or run your own queries with BioBTree MCP.

Datasets: alphafold, alphamissense, antibody, bgee, bindingdb, biogrid, biogrid_interaction, ccds, chembl_activity, chembl_molecule, chembl_target, clinical_trials, clinvar, collectri, diamond_similarity, ensembl, entrez, esm2_similarity, exon, expressionatlas, flybase, gencc, go, gtex, gwas, hgnc, hpa, hpo, intact, interpro, jaspar, mim, mondo, msigdb, orphanet, orthodb, ortholog, pdb, pfam, pharmgkb, reactome, refseq, scxa, scxa_expression, smart, spliceai, string, string_interaction, taxonomy, transcript, uniprot
Generated: 2026-05-26 — For the latest data, query BioBTree directly via MCP or API.
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