TY - JOUR
T1 - Identification of a phosphodiesterase that converts inositol cyclic 1:2-Phosphate to inositol 2-phosphate
AU - Ross, Theodora S.
AU - Majerus, Philip W.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1992/10/5
Y1 - 1992/10/5
N2 - Inositol 2-phosphate (Ins(2)P) has been identified in several cell types. The cellular levels of Ins(2)P appear to be directly correlated with the levels of inositol 1:2-cyclic phosphate (cIns(1:2)P) (Ross, T. S., Wang, F. P., and Majerus, P. W. (1992) J. Biol. Chem. 267, 19919-19923). In this study we have detected an enzyme in extracts from CV-1 cells and rat cerebellum that converts cIns(1:2)P to Ins(2)P and inositol 1-phosphate. This enzyme (designated cyclic hydrolase II) is not the same protein previously designated cIns(1:2)P 2-phosphohydrolase (cyclic hydrolase I). The products, heat inactivation curves, pH optima, and metal dependence of these two activities are different, and the two activities were separated by DEAE and gel filtration chromatography. Mixing of cyclic hydrolase I with cyclic hydrolase II does not effect the activity of either. The Km, of the CV-1 cyclic hydrolase II for D-cIns(1:2)P is 10 μM. The enzyme is approximately 55 kDa as estimated by gel filtration analysis in the presence of sodium chloride and 120 kDa in its absence.
AB - Inositol 2-phosphate (Ins(2)P) has been identified in several cell types. The cellular levels of Ins(2)P appear to be directly correlated with the levels of inositol 1:2-cyclic phosphate (cIns(1:2)P) (Ross, T. S., Wang, F. P., and Majerus, P. W. (1992) J. Biol. Chem. 267, 19919-19923). In this study we have detected an enzyme in extracts from CV-1 cells and rat cerebellum that converts cIns(1:2)P to Ins(2)P and inositol 1-phosphate. This enzyme (designated cyclic hydrolase II) is not the same protein previously designated cIns(1:2)P 2-phosphohydrolase (cyclic hydrolase I). The products, heat inactivation curves, pH optima, and metal dependence of these two activities are different, and the two activities were separated by DEAE and gel filtration chromatography. Mixing of cyclic hydrolase I with cyclic hydrolase II does not effect the activity of either. The Km, of the CV-1 cyclic hydrolase II for D-cIns(1:2)P is 10 μM. The enzyme is approximately 55 kDa as estimated by gel filtration analysis in the presence of sodium chloride and 120 kDa in its absence.
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M3 - Article
C2 - 1328187
AN - SCOPUS:0026701680
SN - 0021-9258
VL - 267
SP - 19924
EP - 19928
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 28
ER -