Existence of phosphoinositide-specific phospholipase C in rat liver nuclei and its change during liver regeneration.
We found phosphoinositide-specific phospholipase C (PtdIns-PLC) activity in nuclei isolated from rat liver. The enzyme hydrolyzed phosphatidylinositol, phosphatidylinositol 4-monophosphate (PIP) and phosphatidylinositol 4,5-bisphosphate in a Ca(2+)-dependent manner, and produced inositol mono-, bis-, and triphosphate, respectively. Neither phosphatidylcholine, phosphatidylethanolamine, nor phosphatidylserine was utilized as a substrate. After partial hepatectomy, the PtdIns-PLC activity in isolated nuclei increased transiently in the S phase (20-22 h post-hepatectomy), to 2.5-fold higher than in the control, when measured with PIP. This result suggests a close relationship between the nuclear PtdIns-PLC, especially its PIP-hydrolyzing activity, and cell proliferation.
Kuriki
H
H
First Department of Surgery, Nagoya University School of Medicine, Aichi.
Tamiya-Koizumi
K
K
Asano
M
M
Yoshida
S
S
Kojima
K
K
Nimura
Y
Y
D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology; D008099:Liver / Q000201:enzymology*; D008115:Liver Regeneration / Q000502:physiology*; D010716:Phosphatidylinositols / Q000378:metabolism*; D051381:Rats; D013347:Subcellular Fractions / Q000201:enzymology; D010738:Type C Phospholipases / Q000032:analysis*
D010716:Phosphatidylinositols; D010738:Type C Phospholipases