A regulatory axis for tonotopic MYO7A expression in cochlear hair cells - PubMed
3 hours ago
- #MYO7A
- #tonotopic expression
- #SIX2
- The Myo7a gene encodes an unconventional myosin crucial for cochlear hair cell function and is associated with Usher syndrome and deafness.
- Cochlear hair cells express two Myo7a isoforms (Myo7a-C and Myo7a-N) from distinct transcriptional start sites, with outer hair cells co-expressing both and inner hair cells primarily expressing Myo7a-C.
- An intronic cis-regulatory element, EnhancerA, is identified as essential for tonotopically graded Myo7a expression, and its deletion reduces protein levels, disrupts hair bundle morphogenesis, alters mechanotransduction, and causes hearing loss.
- The transcription factor SIX2, which is tonotopically expressed, may interact with EnhancerA to regulate Myo7a-N in outer hair cells, defining a cis-trans regulatory axis for isoform-specific expression and cochlear function.