Unexpected cross talk: small GTPase regulation of calcium channel trafficking.
Calcium ions can serve as both charge carriers and second messengers. Most cells have voltage-dependent calcium channels that control the membrane permeability to calcium. These channels at the membrane open in response to changes in membrane potential. Their activity is further modulated by phosphorylation by various kinases, such as protein kinase A and protein kinase C, and by changes in intracellular calcium concentration through the action of calcium calmodulin (Ca(2+)/CaM). Trimmer discusses a potential mechanism by which the expression of these channels can be regulated through an interaction with a small guanosine triphosphatase (GTPase), kir/Gem, that influences trafficking of the channels through effects on assembly with auxiliary subunits that occurs in the biosynthetic pathway.
Trimmer
James S
JS
Department of Biochemistry and Cell Biology and Institute for Cell and Developmental Biology, State University of New York at Stony Brook, Stony Brook, NY 11794 USA. james.trimmer@sunysb.edu
D000818:Animals; D015220:Calcium Channels / Q000378:metabolism / Q000502:physiology*; D020013:Calcium Signaling / Q000502:physiology*; D002463:Cell Membrane Permeability / Q000502:physiology; D006801:Humans; D008564:Membrane Potentials / Q000502:physiology; D020559:Monomeric GTP-Binding Proteins / Q000502:physiology*; D020239:Receptor Cross-Talk / Q000502:physiology*
D015220:Calcium Channels; D020559:Monomeric GTP-Binding Proteins