Inhibition of an archaeal protein phosphatase activity by okadaic acid, microcystin-LR, or calyculin A.
Soluble extracts of the methanogenic archaeon, Methanosarcina thermophila TM-1, contained a divalent metal ion-stimulated protein-serine phosphatase activity. This activity was sensitive to micromolar concentrations of okadaic acid, microcystin-LR, or calyculin A, three compounds thought to be highly specific inhibitors of the type 1/2A/2B genetic superfamily of eukaryotic protein-serine/threonine phosphatases. The observation that each of these three chemically unrelated compounds inhibited this archaeal protein phosphatase activity suggests the existence of structural homology, and perhaps even common genetic ancestry, with the type 1/2A/2B superfamily of protein-serine/threonine phosphatases found in eukaryotic organisms.
Oxenrider
K A
KA
Department of Biochemistry and Anaerobic Microbiology, Virginia Polytechnic Institute and State University, Blacksburg 24061-0308.
Rasche
M E
ME
Thorsteinsson
M V
MV
Kennelly
P J
PJ
D004789:Enzyme Activation; D004988:Ethers, Cyclic / Q000494:pharmacology*; D008387:Marine Toxins; D017020:Methanosarcina / Q000201:enzymology*; D052998:Microcystins; D019319:Okadaic Acid; D010080:Oxazoles / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000494:pharmacology*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013045:Species Specificity; D013379:Substrate Specificity
D004988:Ethers, Cyclic; D008387:Marine Toxins; D052998:Microcystins; D010080:Oxazoles; D010456:Peptides, Cyclic; D019319:Okadaic Acid; C059041:calyculin A; D010749:Phosphoprotein Phosphatases; C057862:cyanoginosin LR