OST4

gene
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Summary

OST4 (oligosaccharyltransferase complex subunit 4, non-catalytic, HGNC:32483) is a protein-coding gene on chromosome 2p23.3, encoding Dolichyl-diphosphooligosaccharide–protein glycosyltransferase subunit 4 (P0C6T2). Subunit of the oligosaccharyl transferase (OST) complex that catalyzes the initial transfer of a defined glycan (Glc(3)Man(9)GlcNAc(2) in eukaryotes) from the lipid carrier dolichol-pyrophosphate to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypep…. It is a selective cancer dependency (DepMap: 29.4% of cell lines).

Involved in protein N-linked glycosylation via asparagine. Part of oligosaccharyltransferase complex A and oligosaccharyltransferase complex B.

Source: NCBI Gene 100128731 — RefSeq curated summary.

At a glance

  • GWAS associations: 7
  • Clinical variants (ClinVar): 3 total
  • Cancer dependency (DepMap): dependent in 29.4% of screened cell lines
  • MANE Select transcript: NM_001134693

Identifiers

Gene identifiers

FieldValue
HGNC IDHGNC:32483
Approved symbolOST4
Nameoligosaccharyltransferase complex subunit 4, non-catalytic
Location2p23.3
Locus typegene with protein product
StatusApproved
Ensembl geneENSG00000228474
Ensembl biotypeprotein_coding
OMIM618932
Entrez100128731

Gene structure

Transcript identifiers

Ensembl transcripts: 9 — 9 protein_coding

ENST00000429985, ENST00000447619, ENST00000456793, ENST00000889858, ENST00000889859, ENST00000889860, ENST00000929679, ENST00000929680, ENST00000929681

RefSeq mRNA: 1 — MANE Select: NM_001134693 NM_001134693

CCDS: CCDS58703

Canonical transcript exons

ENST00000456793 — 3 exons

ExonStartEnd
ENSE000016617212707160127071654
ENSE000017307422707132627071463
ENSE000017925412707047227070721

Expression profiles

Bgee: expression breadth ubiquitous, 253 present calls, max score 99.74.

FANTOM5 (CAGE): breadth ubiquitous, TPM avg 669.7161 / max 4300.2705, expressed in 1828 samples.

FANTOM5 promoters (1 alternative TSS)

Promoter IDTPM avgSamples expressed
27439669.71611828

Top tissues by expression

256 total, by Bgee expression score (0-100, higher = more expressed):

TissueAnatomy IDExpression scoreQuality
monocyteCL:000057699.74gold quality
leukocyteCL:000073899.72gold quality
granulocyteCL:000009499.49gold quality
upper arm skinUBERON:000426399.46gold quality
right adrenal glandUBERON:000123399.43gold quality
right coronary arteryUBERON:000162599.43gold quality
left coronary arteryUBERON:000162699.43gold quality
cardiac muscle of right atriumUBERON:000337999.40gold quality
right adrenal gland cortexUBERON:003582799.40gold quality
smooth muscle tissueUBERON:000113599.39gold quality
left adrenal glandUBERON:000123499.39gold quality
left adrenal gland cortexUBERON:003582599.39gold quality
gall bladderUBERON:000211099.37gold quality
coronary arteryUBERON:000162199.36gold quality
right atrium auricular regionUBERON:000663199.36gold quality
stromal cell of endometriumCL:000225599.35gold quality
endocervixUBERON:000045899.35gold quality
ascending aortaUBERON:000149699.34gold quality
thoracic aortaUBERON:000151599.34gold quality
cardiac atriumUBERON:000208199.34gold quality
muscle layer of sigmoid colonUBERON:003580599.34gold quality
bone marrow cellCL:000209299.33gold quality
left ovaryUBERON:000211999.33gold quality
left ventricle myocardiumUBERON:000656699.32gold quality
esophagogastric junction muscularis propriaUBERON:003584199.31gold quality
descending thoracic aortaUBERON:000234599.30gold quality
aortaUBERON:000094799.29gold quality
adrenal cortexUBERON:000123599.29gold quality
right ovaryUBERON:000211899.29gold quality
mucosa of transverse colonUBERON:000499199.29gold quality

Single-cell (SCXA)

Detected in 20 experiment(s), a significant marker in 12.

ExperimentMarker?Max mean expression
E-GEOD-149689yes8525.57
E-MTAB-10432yes6786.99
E-HCAD-4yes73.40
E-HCAD-5yes31.63
E-MTAB-9221yes25.64
E-CURD-122yes22.63
E-MTAB-8410yes22.38
E-MTAB-6701yes18.52
E-HCAD-10yes16.80
E-MTAB-8142yes13.12
E-HCAD-1yes8.78
E-GEOD-124858no1113.47
E-MTAB-10596no1008.76
E-MTAB-4850no638.22
E-MTAB-7051no598.76

Regulation

Is transcription factor: no

miRNA regulators (miRDB)

42 targeting OST4, top 30 by miRDB confidence (max_score; target_count = how many genes the miRNA targets in total — lower means more specific):

miRNAMax scoreAvg scoremiRNA target_count
HSA-MIR-450A-1-3P100.0069.331837
HSA-MIR-4668-3P100.0068.742635
HSA-MIR-3613-3P100.0076.367965
HSA-MIR-314899.9775.066478
HSA-MIR-1211999.8768.351653
HSA-MIR-4728-5P99.8569.394718
HSA-MIR-6785-5P99.8268.684428
HSA-MIR-3913-5P99.7867.26968
HSA-MIR-149-3P99.7268.223963
HSA-MIR-6883-5P99.6968.053785
HSA-MIR-1212499.6869.172700
HSA-MIR-56799.6368.571219
HSA-MIR-3616-5P99.5567.02989
HSA-MIR-57399.5567.44955
HSA-MIR-312299.5066.33821
HSA-MIR-127599.4767.902749
HSA-MIR-391599.4568.491905
HSA-MIR-6513-5P99.4367.811071
HSA-MIR-29799.4069.581418
HSA-MIR-7109-5P99.1866.131057
HSA-MIR-319698.9663.91326
HSA-MIR-315498.9466.551455
HSA-MIR-887-5P98.8265.901347
HSA-MIR-314998.7767.131639
HSA-MIR-6887-5P98.5668.491295
HSA-MIR-5187-5P98.5467.94952
HSA-MIR-6795-5P98.5268.511277
HSA-MIR-318098.4664.68348
HSA-MIR-3180-3P98.4664.68348
HSA-MIR-6816-5P98.4664.35364

Functional genomics

DepMap (CRISPR cell-line fitness): dependent in 29.4% of screened cell lines.

Literature-anchored findings (GeneRIF, showing 1)

  • This study determined the solution structure of human Ost4 in solvent system using NMR spectroscopy. (PMID:21609714)

Cross-species orthologs

3 orthologs

OrganismSymbolGene ID
danio_rerioost4ENSDARG00000096118
mus_musculusOst4ENSMUSG00000038803
rattus_norvegicusOst4ENSRNOG00000074074

Protein

Protein identifiers

Dolichyl-diphosphooligosaccharide–protein glycosyltransferase subunit 4P0C6T2 (reviewed: P0C6T2)

All UniProt accessions (1): P0C6T2

UniProt curated annotations — full annotation on UniProt →

Function. Subunit of the oligosaccharyl transferase (OST) complex that catalyzes the initial transfer of a defined glycan (Glc(3)Man(9)GlcNAc(2) in eukaryotes) from the lipid carrier dolichol-pyrophosphate to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains, the first step in protein N-glycosylation. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity. Specifically involved in maintaining stability of STT3A-containing OST complexes.

Subunit / interactions. Component of the oligosaccharyltransferase (OST) complex. OST exists in two different complex forms which contain common core subunits RPN1, RPN2, OST48, OST4, DAD1 and TMEM258, either STT3A or STT3B as catalytic subunits, and form-specific accessory subunits. STT3A complex assembly occurs through the formation of 3 subcomplexes. Subcomplex 1 contains RPN1 and TMEM258, subcomplex 2 contains the STT3A-specific subunits STT3A, DC2/OSTC, and KCP2 as well as the core subunit OST4, and subcomplex 3 contains RPN2, DAD1, and OST48. The STT3A complex can form stable complexes with the Sec61 complex or with both the Sec61 and TRAP complexes.

Subcellular location. Endoplasmic reticulum. Endoplasmic reticulum membrane.

Pathway. Protein modification; protein glycosylation.

Similarity. Belongs to the OST4 family.

RefSeq proteins (1): NP_001128165* (*=MANE)

Domains & families (InterPro)

IDNameType
IPR018943OligosaccaryltransferaseFamily
IPR036330Ost4p_sfHomologous_superfamily
IPR051307OST4Family

Pfam: PF10215

Enzyme classification (BRENDA):

  • EC 2.4.99.18 — dolichyl-diphosphooligosaccharide-protein glycotransferase (BRENDA: 84 organisms, 135 substrates, 28 inhibitors, 38 Km, 0 kcat entries)

Substrate kinetics (BRENDA)

29 substrates with measured Km, best-characterized 15. Km ranges are aggregated across organisms/conditions.

SubstrateKm (mM)Measurements
TYR-ASN-LEU-THR-SER-VAL0.05–0.63
ACETYL-ASN-ALA-THR0.08–0.1432
ALA-LEU-GLN-ASN-ALA-THR-ARG0.3–0.3582
ASN-ALA-THR0.56–2.092
DIPHENYL-ALA-LEU-GLU-ASN-ALA-THR-ARG-NH20.072–0.232
TYR-GLN-SER-ASN-SER-THR-MET0.08–0.1272
AC-ASN-ALA-THR-NH221
AC-ASN-LEU-THR-NH211
ACETYL-ASN-LYS-THR0.2781
ACETYL-DFNAT-(4-NITROPHENYLALANINE)-NH20.00091
ACETYL-DFNVT-(4-NITROPHENYLALANINE)-NH20.00121
ACETYL-DQNAT-(4-NITROPHENYLALANINE)-NH20.00081
ACETYL-DVNAS-(4-NITROPHENYLALANINE)-NH20.0031
ACETYL-DVNAT-(4-NITROPHENYLALANINE)-NH20.00111
ACETYL-DVNVT-(4-NITROPHENYLALANINE)-NH20.00141

UniProt features (6 total): topological domain 2, chain 1, transmembrane region 1, mutagenesis site 1, helix 1

Structure

Experimental structures (PDB)

7 structures.

PDBMethodResolution (Å)
9N9JELECTRON MICROSCOPY3.2
6S7OELECTRON MICROSCOPY3.5
6S7TELECTRON MICROSCOPY3.5
8PN9ELECTRON MICROSCOPY3.61
9YGYELECTRON MICROSCOPY4.1
8B6LELECTRON MICROSCOPY7.6
2LATSOLUTION NMR

Predicted structure (AlphaFold)

ModelpLDDTFraction very-high
AF-P0C6T2-F189.550.74

Functional residue map

Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.

Mutagenesis-validated functional residues (1):

PositionPhenotype
23decreases interaction with stt3a, stt3b and rpn1.

Function

Pathways and Gene Ontology

Reactome pathways

5 pathways

IDPathway
R-HSA-446203Asparagine N-linked glycosylation
R-HSA-9694548Maturation of spike protein
R-HSA-9768727Regulation of CDH1 posttranslational processing and trafficking to plasma membrane
R-HSA-9918432Maturation of DENV proteins
R-HSA-9931295PD-L1(CD274) glycosylation and translocation to plasma membrane

MSigDB gene sets: 124 (showing top): REACTOME_ADAPTIVE_IMMUNE_SYSTEM, GOBP_PROTEIN_N_LINKED_GLYCOSYLATION, JOHANSSON_GLIOMAGENESIS_BY_PDGFB_UP, GOBP_CARBOHYDRATE_DERIVATIVE_METABOLIC_PROCESS, REACTOME_ADHERENS_JUNCTIONS_INTERACTIONS, GOBP_CARBOHYDRATE_DERIVATIVE_BIOSYNTHETIC_PROCESS, GOBP_GLYCOPROTEIN_METABOLIC_PROCESS, OSMAN_BLADDER_CANCER_DN, GOCC_TRANSFERASE_COMPLEX, REACTOME_REGULATION_OF_T_CELL_ACTIVATION_BY_CD28_FAMILY, GOCC_MEMBRANE_PROTEIN_COMPLEX, GOCC_NUCLEAR_OUTER_MEMBRANE_ENDOPLASMIC_RETICULUM_MEMBRANE_NETWORK, GOCC_ORGANELLE_SUBCOMPARTMENT, REACTOME_CO_INHIBITION_BY_PD_1, REACTOME_CELL_JUNCTION_ORGANIZATION

GO Biological Process (3): protein N-linked glycosylation (GO:0006487), obsolete protein N-linked glycosylation via asparagine (GO:0018279), obsolete protein glycosylation (GO:0006486)

GO Molecular Function (1): protein binding (GO:0005515)

GO Cellular Component (6): endoplasmic reticulum membrane (GO:0005789), oligosaccharyltransferase complex (GO:0008250), oligosaccharyltransferase complex A (GO:0160226), oligosaccharyltransferase complex B (GO:0160227), endoplasmic reticulum (GO:0005783), membrane (GO:0016020)

Reactome top-level categories

Rollup of top-5 pathways:

CategoryPathways
Post-translational protein modification1
Translation of Structural Proteins1
Regulation of CDH1 Expression and Function1
Dengue Virus Genome Translation and Replication1
Regulation of PD-L1(CD274) Post-translational modification1

GO top-level categories

Rollup of top GO terms by namespace:

CategoryTerms
oligosaccharyltransferase complex2
glycoprotein biosynthetic process1
binding1
organelle membrane1
nuclear outer membrane-endoplasmic reticulum membrane network1
endoplasmic reticulum subcompartment1
endoplasmic reticulum membrane1
membrane protein complex1
endoplasmic reticulum protein-containing complex1
transferase complex1
cytoplasm1
endomembrane system1
intracellular membrane-bounded organelle1
cellular anatomical structure1

Protein interactions and networks

STRING

1060 interactions, top by confidence (×1000):

Protein AProtein BPartner UniProtScore
OST4DAD1P46966995
OST4RPN2P04844993
OST4RPN1P04843992
OST4DDOSTP39656991
OST4STT3AP46977982
OST4STT3BQ8TCJ2970
OST4TMEM258P61165904
OST4TUSC3Q13454858
OST4OSTCQ9NRP0820
OST4MAGT1Q9H0U3754
OST4KRTCAP2Q8N6L1726
OST4SSR3Q9UNL2565
OST4ALG5Q9Y673494
OST4PSMD8P48556484
OST4ALG13Q9NP73455

IntAct

10 interactions, top by confidence:

ABTypeScore
UBQLN1OST4psi-mi:“MI:0915”(physical association)0.560
MSGN1OST4psi-mi:“MI:0915”(physical association)0.560
OST4UBQLN1psi-mi:“MI:0915”(physical association)0.560
DAD1RPN1psi-mi:“MI:0915”(physical association)0.530
OST4ATL3psi-mi:“MI:0914”(association)0.350
MSGN1OST4psi-mi:“MI:0915”(physical association)0.000

BioGRID (111): OST4 (PCA), OST4 (Positive Genetic), OST4 (Two-hybrid), OST4 (Two-hybrid), OST4 (Affinity Capture-RNA), LIN54 (Affinity Capture-MS), SUPT6H (Affinity Capture-MS), GIGYF2 (Affinity Capture-MS), NFXL1 (Affinity Capture-MS), RIF1 (Affinity Capture-MS), ZC3H13 (Affinity Capture-MS), RBM26 (Affinity Capture-MS), RNF10 (Affinity Capture-MS), KRTCAP2 (Affinity Capture-MS), PACRGL (Affinity Capture-MS)

ESM2 similar proteins: A1Z7U3, B0BLS0, B1WNA1, B2ITV2, B2J4U1, B3MFK1, B3N7H1, B4GHS8, B4HSS0, B4J877, B4KQ08, B4MDV2, B4MJN5, B4P417, B4QH87, B5E1E8, P0C179, P0C427, P0C428, P0C6T2, P0CU66, P27387, P41608, P58246, P69674, P69675, Q06FP1, Q06RA5, Q0ZIZ2, Q14FD0, Q2JQR6, Q3M5W2, Q49KX1, Q4VZI7, Q6ENE7, Q6EYH5, Q6EYJ1, Q6EYJ9, Q7HIW5, Q7J193

Diamond homologs: A1Z7U3, B0BLS0, B3MFK1, B3N7H1, B4GHS8, B4HSS0, B4J877, B4KQ08, B4MDV2, B4MJN5, B4P417, B4QH87, B5E1E8, C7J0R5, C7J4U3, P0C6T2, P0CU66, Q54V54, Q8L986, Q99LX8, Q9LHK3, Q9SF57

SIGNOR signaling

2 interactions.

AEffectBMechanism
OST4“form complex”“OST-A complex”binding
OST4“form complex”“OST-B complex”binding

Disease & clinical

Clinical variants and AI predictions

ClinVar

3 variants total. Per-class counts are floors (≥ shown; pagination cap):

ClassificationCount (floor)
Pathogenic0
Likely pathogenic0
Uncertain significance2
Likely benign0
Benign0

Top pathogenic / likely-pathogenic (0)

SpliceAI

174 predictions. Top by Δscore:

VariantEffectΔscore
2:27071320:CGTTA:Cdonor_loss1.0000
2:27071321:GTTA:Gdonor_loss1.0000
2:27071322:TTAC:Tdonor_loss1.0000
2:27071323:TACC:Tdonor_loss1.0000
2:27071325:C:CGdonor_loss1.0000
2:27071349:T:Adonor_gain1.0000
2:27071353:T:TAdonor_gain1.0000
2:27071360:T:TAdonor_gain0.9900
2:27070720:CC:Cacceptor_gain0.9700
2:27070721:CC:Cacceptor_gain0.9700
2:27071464:C:CCacceptor_gain0.9700
2:27070722:CT:Cacceptor_loss0.9400
2:27070723:T:Gacceptor_loss0.9400
2:27071592:G:Adonor_gain0.9400
2:27071324:A:ACdonor_gain0.9300
2:27071325:C:CCdonor_gain0.9300
2:27071459:TCATC:Tacceptor_gain0.9300
2:27071460:CATC:Cacceptor_gain0.9300
2:27071460:CATCC:Cacceptor_gain0.9300
2:27070722:C:CCacceptor_gain0.9200
2:27071462:TCC:Tacceptor_loss0.9200
2:27071463:CCTG:Cacceptor_loss0.9200
2:27071464:C:Tacceptor_loss0.9200
2:27071465:T:Gacceptor_loss0.9200
2:27070719:ACC:Aacceptor_gain0.9100
2:27070720:CCC:Cacceptor_gain0.9100
2:27071466:G:Cacceptor_loss0.9100
2:27071595:TCTGA:Tdonor_loss0.9100
2:27071596:CTGAC:Cdonor_loss0.9100
2:27071597:TGACC:Tdonor_loss0.9100

AlphaMissense

238 scored. Top likely-pathogenic:

VariantProtein changeam_pathogenicity
2:27071420:C:GG15R0.993
2:27071443:A:TL7H0.990
2:27071443:A:GL7P0.983
2:27071395:A:TV23D0.980
2:27071419:C:AG15V0.978
2:27071419:C:TG15D0.977
2:27071410:A:TL18H0.976
2:27071431:G:TA11D0.976
2:27071401:A:TL21H0.975
2:27071420:C:AG15C0.973
2:27071387:G:CH26D0.972
2:27071452:T:AD4V0.965
2:27071398:A:TV22D0.964
2:27071401:A:CL21R0.962
2:27071458:A:TI2N0.962
2:27071410:A:CL18R0.960
2:27071390:A:CY25D0.958
2:27071407:A:GF19S0.958
2:27071422:A:CL14R0.958
2:27071443:A:CL7R0.958
2:27071384:A:CY27D0.954
2:27071378:C:GA29P0.953
2:27071420:C:TG15S0.953
2:27071392:A:GL24P0.951
2:27071453:C:GD4H0.950
2:27071385:G:CH26Q0.948
2:27071385:G:TH26Q0.948
2:27071410:A:GL18P0.947
2:27071427:G:CN12K0.947
2:27071427:G:TN12K0.947

dbSNP variants (sampled 300 via entrez): RS1000267952 (2:27072428 G>C), RS1000791296 (2:27070469 A>G), RS1000822366 (2:27070677 G>C), RS1001155224 (2:27070943 A>C,G), RS1001257327 (2:27071817 T>C), RS1001708483 (2:27071634 C>A,G,T), RS1002379907 (2:27070894 G>C), RS1002410300 (2:27073561 G>A), RS1003827326 (2:27072509 G>A), RS1004199389 (2:27072186 T>A), RS1004717756 (2:27071616 C>G,T), RS1004826033 (2:27071788 G>T), RS1005692566 (2:27072562 C>A,G), RS1005998659 (2:27071086 G>A,C), RS1006029500 (2:27071359 T>C)

Disease associations

OMIM: gene MIM:618932 | disease phenotypes:

GenCC curated gene-disease

Mondo (0):

Orphanet (0):

HPO phenotypes

0 total (0 of 0 shown, HPO-id order):

GWAS associations

7 associations (top):

StudyTraitp-value
GCST010697_14Cortical surface area (min-P)2.000000e-09
GCST010698_75Subcortical volume (min-P)2.000000e-13
GCST010699_41Brain morphology (min-P)2.000000e-08
GCST010700_38Cortical thickness (MOSTest)3.000000e-08
GCST010701_56Cortical surface area (MOSTest)4.000000e-16
GCST010702_20Subcortical volume (MOSTest)2.000000e-64
GCST010703_76Brain morphology (MOSTest)1.000000e-16

EFO canonical traits (2, from GWAS)

EFO IDTrait name
EFO:0004346neuroimaging measurement
EFO:0004840cortical thickness

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

PharmGKB: 1 entry (VIP=true, CPIC=false)

CTD chemical–gene interactions

21 total (human), top 21 by PubMed support.

ChemicalActions (top 5)PubMed papers
bisphenol Adecreases expression, affects expression2
Smokedecreases expression, increases abundance2
aristolochic acid Idecreases expression1
bisphenol Faffects cotreatment, increases expression1
lead acetateincreases expression1
arseniteaffects binding, increases reaction1
isobutyl alcoholaffects cotreatment, decreases expression, increases abundance1
chloropicrinincreases expression1
pyrimidifenincreases expression1
Air Pollutantsdecreases expression, increases abundance1
Cisplatinincreases expression1
Dexamethasoneaffects cotreatment, increases expression1
Doxorubicinaffects expression1
Gasolineaffects cotreatment, decreases expression, increases abundance1
Indomethacinaffects cotreatment, increases expression1
Polycyclic Aromatic Hydrocarbonsaffects cotreatment, decreases expression, increases abundance1
Rotenoneincreases expression1
Tobacco Smoke Pollutionincreases expression1
1-Methyl-3-isobutylxanthineincreases expression, affects cotreatment1
Aflatoxin B1increases expression1
Particulate Matteraffects cotreatment, decreases expression, increases abundance1

Clinical trials (associated diseases)

0 trials via MONDO — disease-level, not drug-specific.

No linked Atlas pages yet — the cross-entity mesh grows as the corpus expands.