Zhu, Jiequan, and Gregory R. Ferrier. Regulation of a voltage-sensitive release mechanism by Ca-calmodulin-dependent kinase in cardiac myocytes. Am J Physiol Heart Circ Physiol 279: H2104–H2115, 2000.—A role for Ca-calmodulin-dependent kinase (CamK) in regulation of the voltagesensitive release mechanism (VSRM) was investigated in guinea pig ventricular myocytes. Voltage clamp was used to separ...

The calcium/calmodulin-dependent protein kinase (CCaMK) is regulated by free Ca2+ and Ca2+-loaded calmodulin. This dual binding is believed to be involved in its regulation and associated physiological functions, although direct experimental evidence for this is lacking. Here we document that site-directed mutations in the calmodulin-binding domain of CCaMK alters its binding capacity to calmod...

We have shown previously (Villalonga, P., López- Alcalá, C., Bosch, M., Chiloeches, A., Rocamora, N., Gil, J., Marais, R., Marshall, C. J., Bachs, O., and Agell, N. (2001) Mol. Cell. Biol. 21, 7345-7354) that calmodulin negatively regulates Ras activation in fibroblasts. Hence, anti-calmodulin drugs (such as W13, trifluoroperazine, or W7) are able to induce Ras/ERK pathway activation under low ...

The calcium-binding protein, calmodulin, has been purified from Xenopus laevis oocytes. This 18,500-dalton protein, pl 4.3, has two high-affinity calcium-binding sites per mole protein having a dissociation constant of 2.8 x 10(-6) M. Full-grown Xenopus oocytes, arrested in late G2 of the meiotic cell cycle, resumed meiosis when microinjected with 60-80 ng (3-4 pmol) of calmodulin in the form o...

Conversion of phosphorylase b to a which is catalyzed by the enzyme phosphorylase kinase is known to require Ca++. Trifluoperazine, an inhibitor of calmodulin-dependent enzymes, was utilized in the present study to clarify the role in vivo of calcium-calmodulin regulation of phosphorylase kinase. Twenty-minute preperfusion of isolated rat ventricles with 10(-5) M trifluoperazine had no effect o...

Intracellular Ca2+ and protein phosphorylation play pivotal roles in long-term potentiation (LTP), a cellular model of learning and memory. Ca2+ regulates multiple intracellular pathways, including the calmodulin-dependent kinases (CaMKs) and the ERKs (extracellular signal-regulated kinases), both of which are required for LTP. However, the mechanism by which Ca2+ activates ERK during LTP remai...

CAKβ (cell adhesion kinase β)/PYK2 (proline-rich tyrosine kinase 2) is the second protein-tyrosine kinase of the FAK (focal adhesion kinase) subfamily. It is different from FAK in that it is activated following an increase in cytoplasmic free Ca2+. In the present study we have investigated how Ca2+ activates CAKβ/ PYK2. Calmodulin-agarose bound CAKβ/PYK2, but not FAK, in the presence of CaCl2. ...

By using a synthetic peptide, KM-14, a protein kinase was detected and partially purified from Mougeotia sp. The peptide contains the sequence of the regulatory light chain of smooth muscle myosin that is phosphorylated by calcium-calmodulin-dependent myosin light chain kinase (MLCK). The Mougeotia kinase was stimulated 40-fold by calcium with half-maximal stimulation occurring at 1.5 micromola...

Chimeric Ca/calmodulin-dependent protein kinase (CCaMK) is characterized by a serine-threonine kinase domain, an autoinhibitory domain, a calmodulin-binding domain and a neural visinin-like domain with three EF-hands. The neural visinin-like Ca-binding domain at the C-terminal end of the CaM-binding domain makes CCaMK unique among all the known calmodulindependent kinases. Biological functions ...