Physical and functional interaction of KV10.1 with Rabaptin-5 impacts ion channel trafficking

K(V)10.1 is a potassium channel expressed in brain and implicated in tumor progression. We have searched for proteins interacting with K(V)10.1 and identified Rabaptin-5, an effector of the Rab5 GTPase. Both proteins co-localize on large early endosomes induced by Rab5 hyperactivity. Silencing of Rabaptin-5 induces down-regulation of recycling of K(V)10.1 channel in transfected cells and reduction of K(V)10.1 current density in cells natively expressing K(V)10.1, indicating a role of Rabaptin-5 in channel trafficking. K(V)10.1 co-localizes, but does not physically interact, with Rab7 and Rab11. Our data highlights the complex control of the amount of K(V)10.1 channels on the cell surface. Structured summary of protein interactions: Rabaptin-5 physically interacts with KV10.1 by anti bait coimmunoprecipitation (View interaction) Rabaptin-5 physically interacts with Rabaptin-5 by two hybrid (View interaction) KV10.1 physically interacts with KV10.1 by two hybrid (View interaction) KV10.1 physically interacts with Rabaptin-5 by anti bait coimmunoprecipitation (View Interaction: 1, 2) RABB and KV10.1 colocalize by fluorescence microscopy (View interaction) Kv10.1 and Rabaptin-5 colocalize by fluorescence microscopy (View interaction) Kv10.1 physically interacts with Rabaptin-5 by two hybrid (View Interaction: 1,2) Kv10.1 and RAB7 colocalize by fluorescence microscopy (View interaction) (C) 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.