Calcium mobilization in permeabilized fibroblasts: effects of inositol trisphosphate, orthovanadate, mitogens phorbol ester, and guanosine triphosphate

Journal Article · Thu Jan 01 00:00:00 EST 1987 · J. Cell. Physiol.; (United States)

DOI:https://doi.org/10.1002/jcp.1041300106· OSTI ID:6486710

Muldoon, L L; Jamieson, Jr, G A; Villereal, M L

Utilizing a digitonin-permeabilized cell system, the authors have studied the release of calcium from a non-mitochondrial intracellular compartment in cultured human fibroblasts (HSWP cells). Addition of 1 mM MgATP to a monolayer of permeabilized cells in a cytosolic media buffered to 150 nM Ca with EGTA rapidly stimulates /sup 45/Ca uptake, and the subsequent addition of the putative intracellular messenger inositol trisphosphate (InsP/sub 3/) induces rapid release of 85% of the /sup 45/Ca taken up in response to ATP. Mitogenic peptides (bradykinin, vasopressin, epidermal growth factor (EGF), and insulin) and orthovanadate, which are effective in mobilizing intracellular Ca in intact cells, have little or no effect when added alone to permeabilized cells. However, in the presence of GTP these agents stimulate accumulation of inositol phosphates and release Ca from the InsP/sub 3/-sensitive pool. These data suggest that a GTP binding protein is involved in receptor mediated activation of phospholipase C, which leads to release of inositol phosphates. The GTP-dependent release of InsP/sub 3/ and the mobilization of /sup 45/Ca from the intracellular compartment are inhibited by pretreatment of cells, prior to permeabilization, with the protrein kinase C activator 12-O-tetradecanoyl-phorbol-13-acetate (TPA). These results suggest that protein kinase C is involved in down-regulation or inhibition of phospholipase C, or the GTP binding protein responsible for relaying the mitogenic signal from the cell surface receptor to the phospholipase C activity.

• Research Organization: Univ. of Chicago, IL
• OSTI ID: 6486710
• Journal Information: J. Cell. Physiol.; (United States), Vol. 130:1
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
CALCIUM 45
MEMBRANE TRANSPORT
PHORBOL ESTERS
BIOLOGICAL EFFECTS
VANADATES
ATP
FIBROBLASTS
GUANYLIC ACID
INOSITOLS
MITOGENS
PERMEABILITY
SODIUM COMPOUNDS
ALKALI METAL COMPOUNDS
ALKALINE EARTH ISOTOPES
ANIMAL CELLS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CALCIUM ISOTOPES
CARBOHYDRATES
CARCINOGENS
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ESTERS
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
ISOTOPES
MONOSACCHARIDES
NUCLEI
NUCLEOTIDES
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
RADIOISOTOPES
SACCHARIDES
SOMATIC CELLS
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
560300* - Chemicals Metabolism & Toxicology
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