the proliferation of hepatocellular carcinoma (hcc) cells is one of the leading causes of liver cancer mortality in humans. the inhibiting effects of matrine on hcc cell proliferation have been studied, but the mechanism of that inhibition has not been fully elucidated. since, apoptosis plays an important role in hcc cell proliferation. we examined the apoptosis-inducing effect of matrine on tu...

Enterotoxigenic Escherichia coli (ETEC) causes diarrhea in travelers, young children and piglets, but the precise pathogenesis of ETEC induced diarrhea is not fully known. Recent investigations have shown that tight junction (TJ) proteins and aquaporin 3 (AQP 3) are contributing factors in bacterial diarrhea. In this study, using immunoblotting and immunohistochemistry analyses, we found that E...

Myosin light chain kinase purified from chicken white skeletal muscle (Mr = 150,000) was significantly larger than both rabbit skeletal (Mr = 87,000) and chicken gizzard smooth (Mr = 130,000) muscle myosin light chain kinases, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Km and Vmax values with rabbit or chicken skeletal, bovine cardiac, and chicken gizzard smooth...

Many non-muscle cells including chromaffin cells contain actin and myosin. The 20,000 dalton light chain subunits of myosin can be phosphorylated by a Ca2+/calmodulin-dependent enzyme, myosin light chain kinase. In tissues other than striated muscle, light chain phosphorylation is required for actin-induced myosin ATPase activity. The possibility that actin and myosin are involved in catecholam...

Purified smooth muscle myosin light chain can be phosphorylated at multiple sites by myosin light chain kinase and protein kinase C. We have determined the sites phosphorylated on myosin light chain in intact bovine tracheal smooth muscle. Stimulation with 10 microM carbachol resulted in 66 +/- 5% monophosphorylated and 11 +/- 2% diphosphorylated myosin light chain after 1 min, and 47 +/- 4% mo...

Smooth muscle myosin light chain kinase is phosphorylated in vitro by protein kinase C purified from human platelets. When myosin light chain kinase which has calmodulin bound is phosphorylated by protein kinase C, 0.8-1.1 mol of phosphate is incorporated per mol of myosin light chain kinase with no effect on its enzyme activity. Phosphorylation of myosin light chain kinase with no calmodulin b...

A number of different protein kinases phosphorylate purified heavy chains or the 20-kDa light chain of smooth muscle myosin. The physiological significance of these phosphorylation reactions has been examined in intact smooth muscle. Myosin heavy chain was slightly phosphorylated (0.08 mol of phosphate/mol) under control conditions in bovine tracheal tissue. Treatment with carbachol, isoprotere...

The phosphorylation of the calmodulin-dependent enzyme myosin light chain kinase, purified from bovine tracheal smooth muscle and human blood platelets, by the catalytic subunit of CAMP-dependent protein kinase and by cGMP-dependent protein kinase was investigated. When myosin light chain kinase which has calmodulin bound is phosphorylated by the catalytic subunit of CAMP-dependent protein kina...