PCDH15 and Usher syndrome: An E3 ubiquitin ligase, Ubr3, genetically and physically interacts with the fly orthologues of the Usher syndrome causing human genes PCDH15 (Protocadherin 15, also known as USH1F), MYO7A (Myosin VIIA, also known as USH1B), and USH1G [also known as Sans (scaffold protein containing ankyrin repeats and SAM domain)].