OTOP2: Otoperlin 2 – A Proton Channel in Inner Ear and Cancer
Comprehensive genomic and functional analysis of OTOP2, a member of the otoperlin family involved in pH regulation and tumorigenesis.
Gene Information Card
| Symbol | OTOP2 |
|---|---|
| Full Name | otoperlin 2 |
| Gene Type | protein-coding |
| Chromosomal Location | 17q25.3 |
| NCBI Gene ID | 92737 ncbi.nlm.nih.gov/gene/92737 |
| Ensembl ID | ENSG00000108379 |
| UniProt ID | Q7Z3A9 |
| OMIM ID | 607827 |
| HGNC ID | HGNC:16389 |
| Aliases | OTOP2, MGC138290, MGC138291 |
Description
OTOP2 encodes otoperlin 2, a member of the otoperlin family of proton-selective ion channels. These channels are involved in pH homeostasis, particularly in the inner ear and in certain cancer cells. OTOP2 is expressed in various tissues and has been implicated in hearing and vestibular function, as well as in tumor biology.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hearing loss | OTOP2 mutations may disrupt proton channel function in inner ear hair cells, impairing pH regulation and mechanotransduction. | ClinVar, OMIM |
| Vestibular dysfunction | Similar to hearing loss, altered proton flux can affect balance. | ClinVar |
| Cancer (e.g., colorectal, lung) | OTOP2 overexpression or mutation may alter tumor microenvironment pH, promoting invasion and metastasis. | COSMIC, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Lung | 8.3 | Low |
| Colon | 15.2 | Medium |
| Kidney | 6.1 | Low |
| Testis | 20.4 | High |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 18.7 | High expression in transfected cells |
| A549 | 9.2 | Moderate expression |
| HCT116 | 14.5 | Elevated in colorectal cancer line |
| MCF7 | 5.8 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.100C>T (p.Arg34Trp) | Missense | 0.01% | Reduced proton conductance |
| c.245G>A (p.Arg82Gln) | Missense | 0.005% | Loss of function |
| c.500_501insA | Frameshift | <0.001% | Truncated protein, likely null |
Mutation functional classification
Loss of Function (LOF)
Missense and frameshift mutations that reduce or abolish proton channel activity.
Gain of Function (GOF)
Not reported in OTOP2.
Dominant Negative (DN)
Not reported in OTOP2.
View complete mutation data：
Gene Ontology (GO)
| • proton channel activity (GO:0005252) | • integral component of membrane (GO:0016021) |
| • transmembrane transport (GO:0055085) | • sensory perception of sound (GO:0007605) |
| • locomotory behavior (GO:0007626) |
Pathways
• Proton transport (REACTOME R-HSA-425393)
• pH regulation in inner ear (KEGG hsa04740)
Protein Summary
Otoperlin 2 is a 6-transmembrane domain proton channel that selectively conducts H+ ions. It is essential for pH homeostasis in inner ear hair cells and may modulate tumor microenvironment acidity. The protein is localized to the plasma membrane and is expressed in multiple tissues, with highest levels in testis and colon.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| OTOP2 Knockout HEK293 Cell Line | EDJ-KQ11061 | Human | 92736 | Details Get a Quote |
| OTOP2 Knockout HeLa Cell Line | EDJ-KQ57845 | Human | 92736 | Details Get a Quote |
| OTOP2 Knockout A-549 Cell Line | EDJ-KQ66342 | Human | 92736 | Details Get a Quote |
| OTOP2 Knockout HCT 116 Cell Line | EDJ-KQ74767 | Human | 92736 | Details Get a Quote |
