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

Journal Article · Thu Jan 01 04:00:00 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), Journal Name: J. Cell. Physiol.; (United States) Vol. 130:1; ISSN JCLLA
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALI METAL COMPOUNDS
ALKALINE EARTH ISOTOPES
ANIMAL CELLS
ATP
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CALCIUM 45
CALCIUM ISOTOPES
CARBOHYDRATES
CARCINOGENS
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ESTERS
EVEN-ODD NUCLEI
FIBROBLASTS
GUANYLIC ACID
INOSITOLS
INTERMEDIATE MASS NUCLEI
ISOTOPES
MEMBRANE TRANSPORT
MITOGENS
MONOSACCHARIDES
NUCLEI
NUCLEOTIDES
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PERMEABILITY
PHORBOL ESTERS
RADIOISOTOPES
SACCHARIDES
SODIUM COMPOUNDS
SOMATIC CELLS
TRANSITION ELEMENT COMPOUNDS
VANADATES
VANADIUM COMPOUNDS