Calmodulin-binding proteins of calcium-independent type in rat brain synaptosomal membranes: their localization and properties.
Some properties of calmodulin(CaM)-binding proteins (CaMBPs) of the Ca(2+)-independent type were investigated in the synaptosomal membrane (SM) from rat brain using the [125I]CaM gel overlay method. When SM was prepared in the presence of Ca2+, Ca(2+)-independent CaM binding was decreased, whereas the Ca(2+)-dependent type was not altered. All Ca(2+)-independent-type CaMBPs were membrane-bound and scarcely present in the soluble fractions. When SM was heat-denatured, the 24/22.5-kDa CaMBPs could no longer be detected by [125]CaM binding and a new component with higher molecular mass (greater than 200 kDa) was shown to bind CaM in a Ca(2+)-independent manner. A possible effect of cAMP- and Ca2+/CaM-dependent phosphorylation on CaM binding was also examined.
Natsukari
N
N
National Institute for Physiological Sciences, Division of Active Transport, Okazaki, Japan.
Miwa
A
A
Fujita
M
M
D000818:Animals; D001923:Brain Chemistry; D002118:Calcium / Q000378:metabolism*; D002148:Calmodulin-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002531:Cerebellum / Q000737:chemistry; D002540:Cerebral Cortex / Q000737:chemistry; D000242:Cyclic AMP / Q000378:metabolism; D010766:Phosphorylation; D011489:Protein Denaturation; D051381:Rats; D013570:Synaptic Membranes / Q000737:chemistry*
D002148:Calmodulin-Binding Proteins; D000242:Cyclic AMP; D002118:Calcium