Cochlin is a protein that in humans is encoded by the COCH gene.[5][6] It is an extracellular matrix (ECM) protein highly abundant in the cochlea and vestibule of the inner ear, constituting the major non-collagen component of the ECM of the inner ear.[7][8] The protein is highly conserved in human, mouse, and chicken, showing 94% and 79% amino acid identity of human to mouse and chicken sequences, respectively.[6]

COCH
Available structures
PDBOrtholog search: PDBe RCSB
Identifiers
AliasesCOCH, COCH-5B2, COCH5B2, DFNA9, cochlin, DFNB110
External IDsOMIM: 603196; MGI: 1278313; HomoloGene: 20868; GeneCards: COCH; OMA:COCH - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001135058
NM_004086
NM_001347720

NM_001198835
NM_007728

RefSeq (protein)

NP_001128530
NP_001334649
NP_004077

NP_001185764
NP_031754

Location (UCSC)Chr 14: 30.87 – 30.9 MbChr 12: 51.64 – 51.65 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

Structure

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Cochlin contains three protein domains: an N-terminal LCCL domain, and two copies of Von Willebrand factor type A domains.[9]

Function

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The gene is expressed in spindle-shaped cells located along nerve fibers between the auditory ganglion and sensory epithelium. These cells accompany neurites at the habenula perforata, the opening through which neurites extend to innervate hair cells. This and the pattern of expression of this gene in chicken inner ear paralleled the histologic findings of acidophilic deposits, consistent with mucopolysaccharide ground substance, in temporal bones from DFNA9 (autosomal dominant nonsyndromic sensorineural deafness 9) patients. Mutations that cause DFNA9 have been reported in this gene.[6]

Cochlin has been identified in the trabecular meshwork (TM) of glaucoma patients, but not in healthy controls. The TM is a filter like area of tissue in the eye; cochlin may have a role in cell adhesion, mechanosensation, and modulation of the TM filter.[10][11]

It is also expressed in follicular dendritic cells in spleen and lymph nodes. Here, cochlin is cleaved by aggrecanases and secreted into blood circulation during inflammation, contributing to the antibacterial innate immune response.[12]

References

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  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000100473Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000020953Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Robertson NG, Lu L, Heller S, Merchant SN, Eavey RD, McKenna M, Nadol JB, Miyamoto RT, Linthicum FH, Lubianca Neto JF, Hudspeth AJ, Seidman CE, Morton CC, Seidman JG (November 1998). "Mutations in a novel cochlear gene cause DFNA9, a human nonsyndromic deafness with vestibular dysfunction". Nature Genetics. 20 (3): 299–303. doi:10.1038/3118. PMID 9806553. S2CID 16350815.
  6. ^ a b c "Entrez Gene: COCH coagulation factor C homolog, cochlin (Limulus polyphemus)".
  7. ^ Robertson NG, Skvorak AB, Yin Y, Weremowicz S, Johnson KR, Kovatch KA, Battey JF, Bieber FR, Morton CC (December 1997). "Mapping and characterization of a novel cochlear gene in human and in mouse: a positional candidate gene for a deafness disorder, DFNA9". Genomics. 46 (3): 345–54. doi:10.1006/geno.1997.5067. PMID 9441737.
  8. ^ Ikezono T, Omori A, Ichinose S, Pawankar R, Watanabe A, Yagi T (March 2001). "Identification of the protein product of the Coch gene (hereditary deafness gene) as the major component of bovine inner ear protein". Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease. 1535 (3): 258–65. doi:10.1016/s0925-4439(00)00101-0. PMID 11278165.
  9. ^ "Cochlin (O43405)". InterPro < EMBL-EBI.
  10. ^ Goel M, Sienkiewicz AE, Picciani R, Lee RK, Bhattacharya SK (2011). "Cochlin induced TREK-1 co-expression and annexin A2 secretion: role in trabecular meshwork cell elongation and motility". PLOS ONE. 6 (8): e23070. Bibcode:2011PLoSO...623070G. doi:10.1371/journal.pone.0023070. PMC 3160293. PMID 21886777.
  11. ^ Picciani R, Desai K, Guduric-Fuchs J, Cogliati T, Morton CC, Bhattacharya SK (September 2007). "Cochlin in the eye: functional implications". Progress in Retinal and Eye Research. 26 (5): 453–69. doi:10.1016/j.preteyeres.2007.06.002. PMC 2064858. PMID 17662637.
  12. ^ Py BF, Gonzalez SF, Long K, Kim MS, Kim YA, Zhu H, Yao J, Degauque N, Villet R, Ymele-Leki P, Gadjeva M, Pier GB, Carroll MC, Yuan J (May 2013). "Cochlin produced by follicular dendritic cells promotes antibacterial innate immunity". Immunity. 38 (5): 1063–72. doi:10.1016/j.immuni.2013.01.015. PMC 3758559. PMID 23684986.

Further reading

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This article incorporates text from the public domain Pfam and InterPro: IPR030743