Mitogen activation of a nuclear alkaline phosphatase in normal activated lymphocytes.
B cell differentiation is punctuated by V(D)J joining in the heavy chain of the pro-B cell, VJ joining in the light chain of the pre-B cell, switch recombination, and somatic hypermutation in the mature B cell. The regulatory signals controlling these events and the developmental program leading to them is poorly understood. We have identified a new phosphatase activity that is expressed in lymphocytes and for which high expression is restricted to mature B cells. This new phosphatase is transiently expressed in nuclear extracts of mitogen-activated splenic B cells. The phosphatase is a monoesterase that is active on both dNMPs and pNPP. The phosphatase has been partially purified by column chromatography and is inhibited by orthovanadate, molybdate, tetramisole, and EDTA and requires Mn2+ for activation. Monoesterase activity requires a pH above the neutral range. The activity profile in the presence of the inhibitors and the requirement for basic pH suggest that this enzyme is an alkaline phosphatase.
Kenter
A L
AL
Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago 60680.
Morgan
L
L
D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000201:enzymology* / Q000276:immunology*; D002454:Cell Differentiation; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology*; D004789:Enzyme Activation / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007739:L Cells; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D008819:Mice, Nude
D008070:Lipopolysaccharides; D000469:Alkaline Phosphatase