Background: The β-adrenergic augmentation of cardiac contraction, by increasing the conductivity of L-type voltage-gated Ca1.2 channels, is of great physiological and pathophysiological importance. Stimulation of β-adrenergic receptors (βAR) activates protein kinase A (PKA) through separation of regulatory (PKAR) from catalytic (PKAC) subunits.
View Article and Find Full Text PDFMutations in the gene, encoding the Gβ subunit of heterotrimeric G proteins, cause Encephalopathy. Patients experience seizures, pointing to abnormal activity of ion channels or neurotransmitter receptors. We studied three Gβ mutations (K78R, I80N and I80T) using computational and functional approaches.
View Article and Find Full Text PDFL-type voltage-gated Ca1.2 channels crucially regulate cardiac muscle contraction. Activation of β-adrenergic receptors (β-AR) augments contraction via protein kinase A (PKA)-induced increase of calcium influx through Ca1.
View Article and Find Full Text PDFThe modulation and regulation of voltage-gated Ca(2+) channels is affected by the pore-forming segments, the cytosolic parts of the channel, and interacting intracellular proteins. In this study we demonstrate a direct physical interaction between the N terminus (NT) and C terminus (CT) of the main subunit of the L-type Ca(2+) channel CaV1.2, α1C, and explore the importance of this interaction for the regulation of the channel.
View Article and Find Full Text PDFNeuronal M-type K(+) channels are heteromers of KCNQ2 and KCNQ3 subunits, and are found in cell bodies, dendrites and the axon initial segment, regulating the firing properties of neurons. By contrast, presynaptic KCNQ2 homomeric channels directly regulate neurotransmitter release. Previously, we have described a mechanism for gating downregulation of KCNQ2 homomeric channels by calmodulin and syntaxin1A.
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