title: PDZD7-MYO7A complex identified in enriched stereocilia membranes.
abstract: While more than 70 genes have been linked to deafness, most of which are expressed in mechanosensory hair cells of the inner ear, a challenge has been to link these genes into molecular pathways. One example is Myo7a (myosin VIIA), in which deafness mutations affect the development and function of the mechanically sensitive stereocilia of hair cells. We describe here a procedure for the isolation of low-abundance protein complexes from stereocilia membrane fractions. Using this procedure, combined with identification and quantitation of proteins with mass spectrometry, we demonstrate that MYO7A forms a complex with PDZD7, a paralog of USH1C and DFNB31. MYO7A and PDZD7 interact in tissue-culture cells, and co-localize to the ankle-link region of stereocilia in wild-type but not Myo7a mutant mice. Our data thus describe a new paradigm for the interrogation of low-abundance protein complexes in hair cell stereocilia and establish an unanticipated link between MYO7A and PDZD7.
authors.affiliation: Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States.
authors.forename: Clive P
authors.initials: CP
authors.lastname: Morgan
authors.affiliation: Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States.
authors.forename: Jocelyn F
authors.initials: JF
authors.lastname: Krey
authors.affiliation: Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, United States.
authors.forename: M'hamed
authors.initials: M
authors.lastname: Grati
authors.affiliation: Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhao
authors.affiliation: Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States.
authors.forename: Shannon
authors.initials: S
authors.lastname: Fallen
authors.affiliation: Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, United States.
authors.forename: Abhiraami
authors.initials: A
authors.lastname: Kannan-Sundhari
authors.affiliation: Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, United States.
authors.forename: Xue Zhong
authors.initials: XZ
authors.lastname: Liu
authors.affiliation: OHSU-PSU School of Public Health, Oregon Health and Science University, Portland, United States.|Graduate School of Dentistry, Kyung Hee University, Seoul, Korea.
authors.forename: Dongseok
authors.initials: D
authors.lastname: Choi
authors.affiliation: Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Müller
authors.affiliation: Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States.
authors.forename: Peter G
authors.identifier: 0000-0002-9787-5860
authors.initials: PG
authors.lastname: Barr-Gillespie
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000032:analysis* / Q000302:isolation & purification; D013058:Mass Spectrometry; D008566:Membranes / Q000737:chemistry*; D051379:Mice; D000081412:Myosin VIIa; D009218:Myosins / Q000032:analysis* / Q000302:isolation & purification; D011485:Protein Binding; D059547:Stereocilia / Q000737:chemistry*
chemical_list: D002352:Carrier Proteins; C000631456:Myo7a protein, mouse; D000081412:Myosin VIIa; C000594656:PDZD7 protein, mouse; D009218:Myosins
keywords: auditory; cell biology; chicken; hair bundle; immunoaffinity; mass spectrometry; mouse; neuroscience; vestibular