Fast inactivation of Shal (K(v)4) K+ channels is regulated by the novel interactor SKIP3 in Drosophila neurons.
Shal K+ (K(v)4) channels across species carry the major A-type K+ current present in neurons. Shal currents are activated by small EPSPs and modulate post-synaptic potentials, backpropagation of action potentials, and induction of LTP. Fast inactivation of Shal channels regulates the impact of this post-synaptic modulation. Here, we introduce SKIP3, as the first protein interactor of Drosophila Shal K+ channels. The SKIP gene encodes three isoforms with multiple protein-protein interaction domains. SKIP3 is nervous system specific and co-localizes with Shal channels in neuronal cell bodies, and in puncta along processes. Using a genetic deficiency of SKIP, we show that the proportion of neurons displaying a very fast inactivation, consistent with Shal channels exclusively in a "fast" gating mode, is increased in the absence of SKIP3. As a scaffold-like protein, SKIP3 is likely to lead to the identification of a novel regulatory complex that modulates Shal channel inactivation.
Diao
Fengqiu
F
Department of Biology, Boston University, 5 Cummington Street, Boston, MA 02215, USA.
Waro
Girma
G
Tsunoda
Susan
S
D000818:Animals; D030801:Animals, Genetically Modified; D001703:Biophysics; D002460:Cell Line; D002478:Cells, Cultured; D004330:Drosophila; D029721:Drosophila Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004558:Electric Stimulation / Q000379:methods; D004625:Embryo, Nonmammalian; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D008564:Membrane Potentials / Q000235:genetics / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051672:Shal Potassium Channels / Q000502:physiology*; D014162:Transfection / Q000379:methods
D029721:Drosophila Proteins; D051672:Shal Potassium Channels; D049452:Green Fluorescent Proteins; C474868:SKIP3 protein, Drosophila; D017346:Protein Serine-Threonine Kinases