title: The large conductance calcium-activated K(+) channel interacts with the small GTPase Rab11b.
abstract: The transduction of sound by the receptor or hair cells of the cochlea leads to the activation of ion channels found in the basal and lateral regions of these cells. Thus, the processing of these transduced signals to the central nervous system is tied to the regulation of baso-lateral ion channels. The large conductance calcium-activated potassium or BK channel was revealed to interact with the small GTPase, Rab11b, which is one of many Rabs found in various endosomal pathways. Immunoelectron microscopy showed the colocalization of these two proteins in receptor cells and auditory neurons. Using Chinese hamster ovary cells as a heterologous expression system, Rab11b increased or decreased BK expression, depending on the overexpression or RNAi knockdown of Rab, respectively. Additional mutation analyses, using a yeast two-hybrid assay, suggested that this GTPase moderately interacts within a region of BK exclusive of the N- or C-terminal tails. These data suggest that this small GTPase regulates BK in a slow recycling process through the endocytic compartment and to the plasmalemma.
authors.affiliation: Otology Laboratory, Dept. of Otolaryngology-HNS, University of South Florida, Morsani College of Medicine, 12901 Bruce B. Downs Blvd., Tampa, FL 33612, USA.
authors.forename: Sophia
authors.initials: S
authors.lastname: Sokolowski
authors.forename: Margaret
authors.initials: M
authors.lastname: Harvey
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Sakai
authors.forename: Amy
authors.initials: A
authors.lastname: Jordan
authors.forename: Bernd
authors.initials: B
authors.lastname: Sokolowski
mesh_terms: D000818:Animals; D016466:CHO Cells; D003051:Cochlea / Q000378:metabolism*; D006224:Cricetinae; D004252:DNA Mutational Analysis; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000099193:rab11 GTP-Binding Proteins
chemical_list: D051036:Large-Conductance Calcium-Activated Potassium Channels; D034741:RNA, Small Interfering; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins