Cyclic hydrolase-transfected 3T3 cells have low levels of inositol 1,2-cyclic phosphate and reach confluence at low density.
The cDNA that encodes inositol-1,2-cyclic phosphate 2-phosphohydrolase (cyclic hydrolase), an enzyme that converts inositol 1,2-cyclic phosphate (cIns(1,2)P) to inositol 1-phosphate, was expressed in 3T3 cells to investigate the function of inositol cyclic phosphates. Cells with increased cyclic hydrolase activity had lower levels of cIns(1,2)P and grew to a lower density at confluence than control cells. This relationship was strengthened by the demonstration that several cell types with differences in cyclic hydrolase activity had levels of cIns(1,2)P and saturation densities that also correlated inversely with cyclic hydrolase activity. In addition, cyclic hydrolase activity is higher in cells at confluence compared to subconfluence. These results suggest that cellular cIns(1,2)P levels are determined by cyclic hydrolase activity and play a role in the control of cell proliferation.
Ross
T S
TS
Division of Hematology-Oncology, Washington University School of Medicine, St. Louis, Missouri 63110.
Whiteley
B
B
Graham
R A
RA
Majerus
P W
PW
D000818:Animals; D017318:Annexin A3; D001483:Base Sequence; D015153:Blotting, Western; D002455:Cell Division; D003001:Cloning, Molecular; D015870:Gene Expression; D007295:Inositol Phosphates / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D010727:Phosphoric Diester Hydrolases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D014162:Transfection
D007295:Inositol Phosphates; D009841:Oligonucleotides; C010199:inositol cyclic phosphate; D010727:Phosphoric Diester Hydrolases; D017318:Annexin A3