Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.11 (AMPK)
 12,425 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasma membranes of pig myometrium show the ability for endogenous phosphorylation (160 +/- 45 pmol 32P/mg.min); the initial rate of this process increases 2.5-fold in the presence of 10(-6) cAMP. Micromolar concentrations of cAMP activate the ATP-dependent transport of Ca2+ in myometrium plasma membranes; cAMP at concentrations of 10(-9)-10(-4) M has no effect on Ca,Mg-ATPase. Myometrium plasma membranes possess the Mg2+-dependent phosphatase activity. Dephosphorylation of membranes is accompanied by a decrease (by 25-50%) of the Ca,Mg-ATPase activity and Ca2+ uptake, respectively. The exogenous catalytic subunit of cAMP-dependent protein kinase increases the activity of Ca,Mg-ATPase in native and dephosphorylated membranes. Tolbutamide diminishes the activity of Ca,Mg-ATPase in native membranes by 25% without causing any appreciable influence on the enzyme activity in dephosphorylated membranes. Taking into account the similarity of dependence of Ca2+ uptake on Ca2+ concentration in native and cAMP-phosphorylated vesicles, it can be assumed that the cAMP-dependent phosphorylation affects the enzyme turnover number but not its affinity for Ca2+. The dephosphorylation-induced inhibition of Ca,Mg-ATPase activity and accumulation of Ca2+ are reversible processes.
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PMID:[cAMP-dependent regulation of the active transport of Ca2+ in plasma membranes of the swine myometrium]. 282 89