Role for a Novel Usher Protein Complex in Hair Cell Synaptic Maturation
Figure 9
Biochemical analysis of the Usher synaptic isoforms.
Panel A: Expression profile of the Usher proteins in differentiated UB/OC-1 cells (OC1), P3 organ of Corti (C) and neuroretina (R). β-actin was used as a loading control. NRS: normal rabbit serum (control). Panel B: Expression of the Usher isoforms in crude synaptosomal preparations from P3 organs of Corti (C) and neuroretina (R). The co-fractionation with RIBEYE (RIB) demonstrates the presence of specific Usher isoforms at the synapses. Panel C: Co-immunoprecipitation analysis in differentiated UB/OC-1 cell membrane fractions. Lanes Usher antibody+M represent specific antibody-coated beads incubated with the membrane fraction. Lanes Usher antibody+B represent specific antibody-coated beads incubated with resuspension buffer only (control 1). Lane NRS+M represents unrelated antibody-coated beads incubated with the membrane fraction (control 2). Lane NO AB+M represents un-coated beads incubated with the membrane fraction (control 3). Arrowheads denote the IgGs from the immunoprecipitation assay. Molecular weight markers are denoted to the left. Isoforms were named according to previously establish nomenclature systems Blots were cropped to show only the results relevant to this study.