Direct connexin-26 interactions with membrane proteins functionally relevant to the cochlea

Area of Science:

• Molecular Biology
• Genetics
• Otolaryngology

Background:

• Connexin 26 (Cx26), encoded by the GJB2 gene, is vital in the cochlea and skin.
• GJB2 mutations cause hearing loss and skin conditions, but the etiology of some cases remains unknown.
• Identifying Cx26 interacting proteins may reveal new genetic factors for hearing loss.

Purpose of the Study:

• To identify direct protein partners of Connexin 26.
• To investigate the relevance of these interactions in cochlear and skin physiology.
• To explore potential links between Cx26 interactors and genetic hearing loss or skin disorders.

Main Methods:

• A human fetal brain cDNA library was screened using a membrane yeast two-hybrid assay to find Cx26 interacting proteins.
• In-silico characterization was performed on identified interactors.
• Coexpression analysis of Cx26 and its interactors was conducted in mouse cochlea and embryonic keratinocytes.

Main Results:

• Forty direct Connexin 26 interactors were identified.
• The mouse Gjb2 orthologue coexpressed with 95% of these interactors in cochlea and 70% in keratinocytes.
• Interactome analysis revealed enrichment of transporter activity, including ion transporters, in cochlear supporting cells. Nine genes were linked to deafness/skin disorders or hearing loss loci.

Conclusions:

• The Connexin 26 interactome includes proteins crucial for cochlear and skin function.
• This network provides potential candidates for understanding genetic hearing loss and associated skin phenotypes.
• The findings highlight the role of Cx26-associated proteins in ion transport and cellular communication relevant to hearing.