Regulation of CaMKII in vivo: the importance of targeting and the intracellular microenvironment.
CaMKII (calcium/calmodulin-stimulated protein kinase II) is a multifunctional protein kinase that regulates normal neuronal function. CaMKII is regulated by multi-site phosphorylation, which can alter enzyme activity, and targeting to cellular microdomains through interactions with binding proteins. These proteins integrate CaMKII into multiple signalling pathways, which lead to varied functional outcomes following CaMKII phosphorylation, depending on the identity and location of the binding partner. A new phosphorylation site on CaMKII (Thr253) has been identified in vivo. Thr253 phosphorylation controls CaMKII purely by targeting, does not effect enzyme activity, and occurs in response to physiological and pathological stimuli in vivo, but only in CaMKII molecules present in specific cellular locations. This new phosphorylation site offers a potentially novel regulatory mechanism for controlling functional responses elicited by CaMKII that are restricted to specific subcellular locations and/or certain cell types, by controlling interactions with proteins that are expressed in the cell at that location.
School of Biomedical Sciences and Hunter Medical Research Institute, Faculty of Health, The University of Newcastle, Callaghan, NSW 2308, Australia.
Kathryn A
KA
Skelding
John A P
JA
Rostas
D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D007424:Intracellular Fluid / Q000201:enzymology*; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D010766:Phosphorylation / Q000502:physiology; D011485:Protein Binding / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D013912:Threonine / Q000378:metabolism
D008565:Membrane Proteins; D013912:Threonine; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2