ROPN1B

Summary

ROPN1B (rhophilin associated tail protein 1B, HGNC:31927) is a protein-coding gene on chromosome 3q21.2, encoding Ropporin-1B (Q9BZX4). Important for male fertility.

Enables protein heterodimerization activity. Predicted to be involved in several processes, including flagellated sperm motility; protein localization to cilium; and sperm capacitation. Located in cytoplasm and motile cilium.

Source: NCBI Gene 152015 — RefSeq curated summary.

At a glance

• Clinical variants (ClinVar): 37 total
• MANE Select transcript: NM_001308313

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:31927
Approved symbol	ROPN1B
Name	rhophilin associated tail protein 1B
Location	3q21.2
Locus type	gene with protein product
Status	Approved
Ensembl gene	ENSG00000114547
Ensembl biotype	protein_coding
Entrez	152015

Gene structure

Transcript identifiers

Ensembl transcripts: 10 — 6 protein_coding, 2 protein_coding_CDS_not_defined, 1 retained_intron, 1 nonsense_mediated_decay

ENST00000251776, ENST00000504401, ENST00000505382, ENST00000508088, ENST00000510450, ENST00000511035, ENST00000511082, ENST00000511862, ENST00000513830, ENST00000514116

RefSeq mRNA: 2 — MANE Select: NM_001308313 NM_001012337, NM_001308313

CCDS: CCDS33841

Canonical transcript exons

ENST00000514116 — 7 exons

Exon	Start	End
ENSE00002077138	125983254	125983454
ENSE00002367498	125971117	125971162
ENSE00002402332	125982270	125982445
ENSE00002405653	125969178	125969400
ENSE00003481318	125977004	125977165
ENSE00003591525	125972043	125972170
ENSE00003666038	125975563	125975680

Expression profiles

Bgee: expression breadth ubiquitous, 130 present calls, max score 98.79.

FANTOM5 (CAGE): breadth tissue_specific, TPM avg 0.0683 / max 69.4671, expressed in 5 samples.

FANTOM5 promoters (5 alternative TSS)

Promoter ID	TPM avg	Samples expressed
202907	0.0293	4
202910	0.0121	3
202906	0.0091	3
202908	0.0090	4
202909	0.0088	2

Top tissues by expression

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

Tissue	Anatomy ID	Expression score	Quality
left testis	UBERON:0004533	98.79	gold quality
right testis	UBERON:0004534	98.48	gold quality
testis	UBERON:0000473	98.38	gold quality
male germ line stem cell (sensu Vertebrata) in testis	CL:0000089 ∩ UBERON:0000473	86.72	gold quality
primordial germ cell in gonad	CL:0000670 ∩ UBERON:0000991	86.64	gold quality
olfactory segment of nasal mucosa	UBERON:0005386	80.51	gold quality
saliva-secreting gland	UBERON:0001044	76.70	gold quality
skin of leg	UBERON:0001511	76.35	gold quality
minor salivary gland	UBERON:0001830	75.79	gold quality
zone of skin	UBERON:0000014	75.62	gold quality
apex of heart	UBERON:0002098	75.33	gold quality
skin of abdomen	UBERON:0001416	74.83	gold quality
heart left ventricle	UBERON:0002084	72.54	gold quality
putamen	UBERON:0001874	72.37	gold quality
caudate nucleus	UBERON:0001873	72.34	gold quality
pituitary gland	UBERON:0000007	72.32	gold quality
tibial nerve	UBERON:0001323	72.22	gold quality
nucleus accumbens	UBERON:0001882	72.09	gold quality
adenohypophysis	UBERON:0002196	70.33	gold quality
prefrontal cortex	UBERON:0000451	70.19	gold quality
heart	UBERON:0000948	69.47	gold quality
frontal cortex	UBERON:0001870	69.04	gold quality
right atrium auricular region	UBERON:0006631	68.36	gold quality
anterior cingulate cortex	UBERON:0009835	68.13	gold quality
brain	UBERON:0000955	68.11	gold quality
thoracic mammary gland	UBERON:0005200	68.05	gold quality
dorsolateral prefrontal cortex	UBERON:0009834	67.82	gold quality
right frontal lobe	UBERON:0002810	67.73	gold quality
cerebral cortex	UBERON:0000956	67.39	gold quality
right hemisphere of cerebellum	UBERON:0014890	67.34	gold quality

Single-cell (SCXA)

Detected in 2 experiment(s), a significant marker in 2.

Experiment	Marker?	Max mean expression
E-GEOD-134144	yes	28.17
E-ANND-3	yes	4.63

Regulation

Is transcription factor: no

miRNA regulators (miRDB)

12 targeting ROPN1B, top 30 by miRDB confidence (max_score; target_count = how many genes the miRNA targets in total — lower means more specific):

miRNA	Max score	Avg score	miRNA target_count
HSA-MIR-8068	99.98	73.85	2376
HSA-LET-7C-3P	99.95	73.42	2862
HSA-MIR-141-5P	99.57	67.86	897
HSA-MIR-6839-3P	99.39	68.86	1301
HSA-MIR-382-3P	98.83	67.10	1074
HSA-MIR-629-5P	98.78	68.72	1032
HSA-MIR-3192-3P	98.62	65.80	970
HSA-MIR-3613-5P	98.40	68.91	604
HSA-MIR-1285-5P	98.01	68.71	779
HSA-MIR-5585-5P	97.95	68.80	1024
HSA-MIR-4695-3P	96.71	67.21	836
HSA-MIR-6802-5P	94.94	65.95	366

Cross-species orthologs

2 orthologs

Organism	Symbol	Gene ID
mus_musculus	Ropn1	ENSMUSG00000022832
rattus_norvegicus	Ropn1	ENSRNOG00000002187

Paralogs (2): ROPN1 (ENSG00000065371), ROPN1L (ENSG00000145491)

Protein

Protein identifiers

Ropporin-1B — Q9BZX4 (reviewed: Q9BZX4)

Alternative names: Rhophilin-associated protein 1B

All UniProt accessions (5): Q9BZX4, A0A140VKG6, D6RA85, D6RAA3, D6RCR2

UniProt curated annotations — full annotation on UniProt →

Function. Important for male fertility. With ROPN1L, involved in fibrous sheath integrity and sperm motility, plays a role in PKA-dependent signaling processes required for spermatozoa capacitation.

Subunit / interactions. Homodimer. Interacts with RHPN1. May interact with SPA17. Interacts with AKAP3. Interacts with FSCB; the interaction increases upon spermatozoa capacitation conditions.

Subcellular location. Cell projection. Cilium. Flagellum.

Post-translational modifications. Sumoylated, sumoylation decreases upon spermatozoa capacitation conditions.

Domain organisation. The RIIa domain mediates interaction with AKAP3.

Miscellaneous. ‘Ropporin’ comes from the Japanese word ‘oppo’ which means ’tail’.

Similarity. Belongs to the ropporin family.

Isoforms (2)

UniProt ID	Names	Canonical?
Q9BZX4-1	1	yes
Q9BZX4-2	2

RefSeq proteins (2): NP_001012337, NP_001295242* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR047844	ROP_DD	Domain

UniProt features (6 total): chain 1, domain 1, region of interest 1, modified residue 1, splice variant 1, mutagenesis site 1

Structure

Experimental structures (PDB)

0 structures.

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-Q9BZX4-F1	85.33	0.56

Functional residue map

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

Post-translational modifications (1): 56

Mutagenesis-validated functional residues (1):

Position	Phenotype
18	abolishes interaction with akap3.

Function

Pathways and Gene Ontology

Reactome pathways

0 pathways

MSigDB gene sets: 69 (showing top): GOBP_SINGLE_FERTILIZATION, GOBP_PROTEIN_LOCALIZATION_TO_CILIUM, GOBP_MEMBRANE_FUSION, GOBP_PLASMA_MEMBRANE_ORGANIZATION, GOBP_MALE_GAMETE_GENERATION, GOBP_SPERM_CAPACITATION, GOBP_CELL_CELL_ADHESION, GOBP_ANATOMICAL_STRUCTURE_MATURATION, GOBP_CYTOKINESIS, GOBP_CELL_MATURATION, GOBP_CILIUM_ORGANIZATION, GOBP_CILIUM_MOVEMENT, GOBP_CILIUM_OR_FLAGELLUM_DEPENDENT_CELL_MOTILITY, GOBP_CELLULAR_PROCESS_INVOLVED_IN_REPRODUCTION_IN_MULTICELLULAR_ORGANISM, GOBP_ENDOMEMBRANE_SYSTEM_ORGANIZATION

GO Biological Process (10): Rho protein signal transduction (GO:0007266), spermatogenesis (GO:0007283), acrosome reaction (GO:0007340), fusion of sperm to egg plasma membrane involved in single fertilization (GO:0007342), flagellated sperm motility (GO:0030317), cilium organization (GO:0044782), sperm capacitation (GO:0048240), protein localization to cilium (GO:0061512), cytoskeleton-dependent cytokinesis (GO:0061640), cell-cell adhesion (GO:0098609)

GO Molecular Function (3): signaling receptor complex adaptor activity (GO:0030159), protein heterodimerization activity (GO:0046982), protein binding (GO:0005515)

GO Cellular Component (4): cytoplasm (GO:0005737), motile cilium (GO:0031514), cilium (GO:0005929), cell projection (GO:0042995)

GO top-level categories

Rollup of top GO terms by namespace:

Category	Terms
developmental process involved in reproduction	2
single fertilization	2
cellular process involved in reproduction in multicellular organism	2
cellular anatomical structure	2
small GTPase-mediated signal transduction	1
male gamete generation	1
membrane fusion involved in acrosome reaction	1
reproductive process	1
acrosomal vesicle exocytosis	1
cilium-dependent cell motility	1
cilium movement involved in cell motility	1
sperm motility	1
organelle organization	1
plasma membrane bounded cell projection organization	1
spermatid development	1
cell maturation	1
protein localization to organelle	1
cytokinesis	1
cell adhesion	1
signaling receptor binding	1
signaling adaptor activity	1
protein dimerization activity	1
binding	1
intracellular anatomical structure	1
cilium	1
intraciliary transport particle	1
membrane-bounded organelle	1
plasma membrane bounded cell projection	1

Protein interactions and networks

STRING

330 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
ROPN1B	TEX55	Q96M34	570
ROPN1B	CATIP	Q7Z7H3	502
ROPN1B	EFCAB10	A6NFE3	475
ROPN1B	AKAP4	Q5JQC9	464
ROPN1B	AKAP3	O75969	449
ROPN1B	CLVS2	Q5SYC1	394
ROPN1B	TRIM2	Q9C040	394
ROPN1B	ZACN	Q401N2	378
ROPN1B	RIIAD1	A6NNX1	370
ROPN1B	TPGS1	Q6ZTW0	364
ROPN1B	C8orf34	Q49A92	348
ROPN1B	GPM6B	Q13491	325
ROPN1B	NKAIN1	Q4KMZ8	316
ROPN1B	SUSD3	Q96L08	316
ROPN1B	CABYR	O75952	306

IntAct

6 interactions, top by confidence:

A	B	Type	Score
ROPN1	PRKAR2B	psi-mi:“MI:0914”(association)	0.530
ROPN1B	AKAP3	psi-mi:“MI:0915”(physical association)	0.510
AKAP3	ROPN1B	psi-mi:“MI:0915”(physical association)	0.510
ROPN1	SLC27A2	psi-mi:“MI:0914”(association)	0.350
ROPN1	PPM1B	psi-mi:“MI:0914”(association)	0.350

BioGRID (3): ROPN1B (Affinity Capture-MS), ROPN1B (Affinity Capture-MS), ROPN1B (Two-hybrid)

ESM2 similar proteins: A6NFE3, B3LF48, C7A639, F1SSF9, I2DDG2, O13728, P02635, P02636, P05946, P08733, P14202, P32070, P45961, P81128, P83509, P97393, Q01449, Q02045, Q13017, Q3SZE5, Q3T064, Q4KLL5, Q4R6C5, Q4V7T8, Q52K82, Q54MF3, Q5E9G1, Q5R629, Q66IC9, Q6AXZ3, Q6DCF6, Q6DJ05, Q6NU25, Q803V3, Q91YM2, Q94CF0, Q969Q6, Q96C74, Q9BZX4, Q9D581

Diamond homologs: P86196, Q3T064, Q4KLL5, Q4R6C5, Q9BZX4, Q9ESG2, Q9HAT0, Q3T024, Q4R760, Q4V7T8, Q66IC9, Q96C74, Q9EQ00, P13861

SIGNOR signaling

0 interactions.

Disease & clinical

Clinical variants and AI predictions

ClinVar

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

Classification	Count (floor)
Pathogenic	0
Likely pathogenic	0
Uncertain significance	30
Likely benign	4
Benign	0

Top pathogenic / likely-pathogenic (0)

SpliceAI

787 predictions. Top by Δscore:

Variant	Effect	Δscore
3:125972166:GCCGA:G	donor_gain	1.0000
3:125972169:GA:G	donor_gain	1.0000
3:125972171:G:GG	donor_gain	1.0000
3:125975561:A:AG	acceptor_gain	1.0000
3:125975562:G:GG	acceptor_gain	1.0000
3:125977129:G:GT	donor_gain	1.0000
3:125977160:G:GT	donor_gain	1.0000
3:125977161:GAGTT:G	donor_gain	1.0000
3:125977163:GTT:G	donor_gain	1.0000
3:125977163:GTTGT:G	donor_loss	1.0000
3:125977164:TT:T	donor_gain	1.0000
3:125977164:TTGTA:T	donor_loss	1.0000
3:125977165:TGTA:T	donor_loss	1.0000
3:125977166:G:GG	donor_gain	1.0000
3:125977166:GTAAG:G	donor_loss	1.0000
3:125977167:TAA:T	donor_loss	1.0000
3:125977168:A:AG	donor_loss	1.0000
3:125977169:AGTT:A	donor_loss	1.0000
3:125972040:TA:T	acceptor_loss	0.9900
3:125972041:A:AG	acceptor_gain	0.9900
3:125972041:A:T	acceptor_loss	0.9900
3:125972042:G:GC	acceptor_gain	0.9900
3:125972042:G:T	acceptor_loss	0.9900
3:125972148:G:GT	donor_gain	0.9900
3:125972169:GAGT:G	donor_loss	0.9900
3:125972170:AG:A	donor_loss	0.9900
3:125972171:G:C	donor_loss	0.9900
3:125972172:TACGT:T	donor_loss	0.9900
3:125972205:G:GT	donor_gain	0.9900
3:125973083:GC:G	donor_gain	0.9900

AlphaMissense

1378 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
3:125977124:T:A	W119R	0.990
3:125977124:T:C	W119R	0.990
3:125977049:T:A	W94R	0.981
3:125977049:T:C	W94R	0.981
3:125972115:T:C	F21L	0.978
3:125972117:T:A	F21L	0.978
3:125972117:T:G	F21L	0.978
3:125983288:T:C	F203L	0.977
3:125983289:T:C	F203S	0.977
3:125983290:T:A	F203L	0.977
3:125983290:T:G	F203L	0.977
3:125982354:T:C	F161L	0.976
3:125982356:C:A	F161L	0.976
3:125982356:C:G	F161L	0.976
3:125975661:T:C	L72S	0.972
3:125982366:T:G	Y165D	0.969
3:125977133:T:C	F122L	0.968
3:125977135:T:A	F122L	0.968
3:125977135:T:G	F122L	0.968
3:125982360:T:C	F163L	0.968
3:125982362:T:A	F163L	0.968
3:125982362:T:G	F163L	0.968
3:125977126:G:C	W119C	0.965
3:125977126:G:T	W119C	0.965
3:125982286:T:C	L138P	0.963
3:125982345:T:C	F158L	0.963
3:125982347:C:A	F158L	0.963
3:125982347:C:G	F158L	0.963
3:125977134:T:C	F122S	0.959
3:125982379:C:A	A169D	0.959

dbSNP variants (sampled 300 via entrez): RS1000888964 (3:125979550 G>A,C,T), RS1000948651 (3:125973491 T>C), RS1001085977 (3:125979267 T>C), RS1001206468 (3:125979968 C>T), RS1001279851 (3:125979888 G>A), RS1001387901 (3:125973177 G>A,T), RS1001512495 (3:125967637 C>T), RS1001822370 (3:125973962 G>A), RS1002259102 (3:125978897 C>G,T), RS1002745216 (3:125973056 T>C,G), RS1003229709 (3:125972746 G>A), RS1003318959 (3:125976723 T>A), RS1003424019 (3:125983037 A>T), RS1003669073 (3:125977333 G>T), RS1003778654 (3:125971589 A>G)

Disease associations

OMIM: gene `` | disease phenotypes:

GenCC curated gene-disease

Mondo (0):

Orphanet (0):

HPO phenotypes

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

GWAS associations

0 associations (top):

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

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

CTD chemical–gene interactions

9 total (human), top 9 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
trichostatin A	increases expression	1
sodium arsenite	affects methylation	1
4-nonylphenol	affects cotreatment, increases expression	1
4-tert-octylphenol	increases expression, affects cotreatment	1
Air Pollutants	increases abundance, increases expression	1
Benzo(a)pyrene	affects methylation, increases methylation	1
Smoke	increases abundance, increases expression	1
Tobacco Smoke Pollution	decreases expression	1
Valproic Acid	decreases methylation	1

Clinical trials (associated diseases)

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