A Protein-Serine Phosphatase from the Halophilic Archaeon Haloferax volcanii

• Published in: Biochemical and biophysical research communications Vol. 194; no. 3; pp. 1330 - 1335
• Main Authors: Oxenrider, K.A., Kennelly, P.J.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 16.08.1993; Elsevier
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Cadmium - pharmacology; Cations, Divalent - pharmacology; Enzyme Activation; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Halobacteriales - enzymology; Hydrolases; Manganese - pharmacology; Phosphoprotein Phosphatases - antagonists & inhibitors; Phosphoprotein Phosphatases - isolation & purification; Phosphoprotein Phosphatases - metabolism; Phosphoproteins - metabolism; Substrate Specificity; Enzymatic activity; Archaeobacteria; Enzyme; Phosphoprotein phosphatase; Biological evolution; Haloferax; Bacteria; Halobacteriaceae
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1993.1970

We have detected a protein phosphatase activity in soluble extracts from the halophilic archaeon Haloferax volcanii. This activity was markedly stimulated by the divalent metal ions Mn 2+ and Cd 2+. It dephosphorylated phosphoseryl residues in casein, mixed histones, and phosphorylase a, but not phosphotyrosyl residues in reduced, carboxyamidomethylated and maleylated lysozyme. This protein phosphatase activity was inhibited by NaF, Zn 2+, vanadate, molybdate, inorganic phosphate, inorganic pyrophosphate, or p-nitrophenyl phosphate, or by treatment with diethylpyrocarbonate. Activity was unaffected by other potential inhibitors or activators such as polyamines, heparin, cyclic nucleotides, Ca 2+/calmodulin, tartrate, tetramisole, okadaic acid, microcystin LR, or sulfhydryl-modifying agents. The functional similarities between this proteinserine phosphatase and that previously identified in another archaeon, the extreme acidothermophile Sulfolobus solfataricus, suggest the existence of a family of divalent metal ion-stimulated protein-serine phosphatases of extremely ancient origin in the Archaea.