title: Usher syndrome: molecular links of pathogenesis, proteins and pathways.
abstract: Usher syndrome is the most common form of deaf-blindness. The syndrome is both clinically and genetically heterogeneous, and to date, eight causative genes have been identified. The proteins encoded by these genes are part of a dynamic protein complex that is present in hair cells of the inner ear and in photoreceptor cells of the retina. The localization of the Usher proteins and the phenotype in animal models indicate that the Usher protein complex is essential in the morphogenesis of the stereocilia bundle in hair cells and in the calycal processes of photoreceptor cells. In addition, the Usher proteins are important in the synaptic processes of both cell types. The association of other proteins with the complex indicates functional links to a number of basic cell-biological processes. Prominently present is the connection to the dynamics of the actin cytoskeleton, involved in cellular morphology, cell polarity and cell-cell interactions. The Usher protein complex can also be linked to the cadherins/catenins in the adherens junction-associated protein complexes, suggesting a role in cell polarity and tissue organization. A third link can be established to the integrin transmembrane signaling network. The Usher interactome, as outlined in this review, participates in pathways common in inner ear and retina that are disrupted in the Usher syndrome.
authors.affiliation: Department of Otorhinolaryngology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. h.kremer@antrg.umcn.nl
authors.forename: Hannie
authors.initials: H
authors.lastname: Kremer
authors.forename: Erwin
authors.initials: E
authors.lastname: van Wijk
authors.forename: Tina
authors.initials: T
authors.lastname: Märker
authors.forename: Uwe
authors.initials: U
authors.lastname: Wolfrum
authors.forename: Ronald
authors.initials: R
authors.lastname: Roepman
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000235:genetics; D000818:Animals; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D007758:Ear, Inner / Q000378:metabolism; D006198:Hair Cells, Auditory / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics; D051379:Mice; D046912:Multiprotein Complexes; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D012160:Retina / Q000378:metabolism; D013569:Synapses / Q000378:metabolism; D052245:Usher Syndromes / Q000209:etiology / Q000235:genetics* / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; D046912:Multiprotein Complexes; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; C118970:USH1C protein, human; C477452:USH1G protein, human; C477219:WHRN protein, human