The long-term objective of this research is to understand the biological role of Ca2+-dependent protein phosphorylation. Increased intracellular Ca2+ generated by cell stimulation is known to regulate a broad range of cellular events such as egg fertilization, secretion, muscle contraction, gene expression and many others. One pivotal class of mediators of the effects of Ca2+ are Ca2+-dependent protein kinases, the majority of which are dependent for their activity upon Ca2+ complexed with calmodulin (CaM). The impetus for this research is the discovery of two novel CaM-dependent protein kinases, CaM kinases Ia and Ib, and the finding that they are themselves regulated by phosphorylation. Definition of the mechanisms by which CaM kinase Ia and lb are regulated is likely to aid in the identification of extracellular signals acting in concert with those regulating intracellular Ca2+ to control cellular function. Since the proteins involved in this regulation, CaM kinase Ia activators and CaM kinase lb kinase may be newly discovered they have the potential to participate in the regulation of other cellular activities and therefore be of broad biological significance. A recent report suggests a potential role for CaM kinases Ia and lb in the pathogenesis of Alzheimer's disease. The specific aims of this project are: Specific Aim l: Purification and characterization of proteins which regulate CaM kinase Ia and CaM kinase Ib. The main objectives are to determine if CaM kinase Ia activators and CaM kinase Ib kinase are previously unrecognized proteins. Specific Aim 2: Mechanisms for the regulation of CaM kinase Ia and Ib. The main objectives are to understand the role of phosphorylation in the activation of CaM kinases Ia and Ib and to determine if CaM kinase Ia activators and CaM kinase Ib kinase are also regulated by phosphorylation.