2020年8月13日 星期四

CaMKII: a multifunctional mediator of calcium signals

CaMKII: a multifunctional mediator of calcium signals

  Roger J. Colbran, Ph.D.

  Professor and Interim Chair, Department of Molecular Physiology and Biophysics, Vanderbilt University, USA

  Associate Editor, Journal of Biological Chemistry

  Time: 9:30-11:00 AM, October 27, 2016

  Venue: C101, Institute of Zoology, CAS

  Host: Professor Feng Liu

  Abstract: 

  Transient changes in intracellular Ca2+ concentrations regulate diverse cellular functions. Cellular responses are often dependent on changes in amplitude, duration, and frequency of these Ca2+ transients. These changes in signal parameters can be integrated by Ca2+/calmodulin-dependent autophosphorylation of dodecameric CaMKII holoenzymes at Thr286. The Thr286 autophosphorylated CaMKII retains Ca2+-independent protein kinase activity that prolongs cellular signaling after cessation of Ca2+ transients. The Colbran lab has focused on testing an over-arching hypothesis that multiple CaMKII-associated proteins (CaMKAPs) target CaMKII holoenzymes to distinct subcellular domains, providing an added layer of regulation by exposing them to different Ca2+ signals and counter-regulatory protein phosphatases. Moreover, CaMKII holoenzymes can be co-localized with different substrates to mediate distinct downstream signals. Several different classes of CaMKAP have been characterized, which interact with CaMKII holoenzymes by distinct mechanisms and exert unique functional effects. Interestingly, several CaMKAPs target CaMKII holoenzymes to plasma membrane ligand- or voltage-gated calcium channels. I will present data showing that the interactions of CaMKII with some of these CaMKAPs are important for feedback regulation of these channels, as well as for downstream signaling in different contexts.