Activation of oocyte phosphatidylinositol kinase by polyamines. [Xenopus laevis]

Conference · Fri May 01 04:00:00 EDT 1987 · Federation Proceedings, Federation of American Societies for Experimental Biology; (USA)

OSTI ID:5052718

Allende, J E; Carrasco, D; Allende, C C ^[1]

---

1. Univ. of Chile, Santiago (Chile)

Membrane bound phosphatidylinositol is phosphorylated by a specific membrane enzyme to form phosphatidylinositol 4 phosphate (PIP) which in turn is again phosphorylated to generate phosphatidylinositol 4,5 biphosphate (PIPP). The regulation of phosphatidylinositol phosphorylation and hydrolysis is relevant to the possible role of inositol phosphates as second messengers of hormone action. The membranes of Xenopus laevis oocytes contain a phosphatidylinositol kinase that can generate radioactive PIP after incubation with ({sup 32}ATP). The radioactive product is extracted with methanol-chloroform and isolated by thin layer chromatography. The oocyte enzyme has an app Km for ATP of 80 {mu}M and cannot use GTP as a phosphate donor. The formation of PIP is greatly stimulated by the addition of synthetic peptides containing clusters of polylysine at concentrations 0.5 mM. A similar effect is observed with a lysine rich peptide that corresponds to the 14 amino acids of the carboxyl terminus of the Kirstein ras 2 protein and also by polyornithine. Polyarginine and histone H{sub 1} have much lower effects. Peptides containing polylysine clusters have also been found to affect the activity of other key membrane enzymes such as protein kinases and adenylate cyclase.

• OSTI ID: 5052718
• Report Number(s): CONF-870644--
• Conference Information: Journal Name: Federation Proceedings, Federation of American Societies for Experimental Biology; (USA) Journal Volume: 46:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ATP
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL ACTIVATION
CHEMICAL REACTIONS
CYCLASES
DAYS LIVING RADIOISOTOPES
DECOMPOSITION
ENZYME ACTIVITY
ENZYMES
ESTERS
GERM CELLS
HYDROLYSIS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIGHT NUCLEI
LIPIDS
LYASES
LYSIS
MEMBRANES
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PEPTIDES
PHOSPHOLIPIDS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
SOLVOLYSIS
TRACER TECHNIQUES
TRANSFERASES