Neurotransmitter modulation of small-conductance Ca2+-activated K+ channels by regulation of Ca2+ gating.

ABSTRACT: Small-conductance Ca2+-activated K+ (SK) channels are widely expressed in neuronal tissues where they underlie post-spike hyperpolarizations, regulate spike-frequency adaptation, and shape synaptic responses. SK channels constitutively interact with calmodulin (CaM), which serves as Ca2+ sensor, and with protein kinase CK2 and protein phosphatase 2A, which modulate their Ca2+ gating. By recording coupled activities of Ca2+ and SK2 channels, we showed that SK2 channels can be inhibited by neurotransmitters independently of changes in the activity of the priming Ca2+ channels. This inhibition involvesSK2-associated CK2 and results from a 3-fold reduction in the Ca2+ sensitivity of channel gating. CK2phosphorylated SK2-bound CaM but not KCNQ2-bound CaM, thereby selectively regulating SK2 chan

SUBMITTER: Maingret F 

PROVIDER: S-EPMC2651825 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature