Document Detail


Expression of a G protein subunit, alpha i-1, in Balb/c 3T3 cells leads to agonist-specific changes in growth regulation.
MedLine Citation:
PMID:  1939086     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Cellular receptors for many hormones, neurotransmitters, and growth factors are coupled to intracellular effector enzymes or ion channels through a set of heterotrimeric G proteins. In order to determine whether isoforms of G protein alpha subunits contribute differentially to mitogenic responses, we introduced an alpha subunit isoform, alpha i-1, into Balb/c 3T3 cells that normally lack this subtype. Balb/c 3T3 cells transfected with a plasmid containing cDNA encoding alpha i-1 expressed the alpha i-1 protein as judged both by the appearance of immunoreactive alpha i-1 protein on Western blots and by two-dimensional analysis of the proteins [32P]ADP-ribosylated by pertussis toxin. The amount of alpha i-1 expressed is less than the amount of alpha subunits endogenously present in these cells. Expression of alpha i-1 in the transfected cells slightly blunts stimulation of adenylylcyclase by GTP, guanosine 5'-3-O-(thio)triphosphate, or forskolin, but has no major effect on the ability of thrombin to inhibit the enzyme. In contrast, the expression of alpha i-1 has significant effects on cell growth and on the mitogenic response to thrombin. The alpha i-1-transfected cells have a doubling time that is twice as long as control cells transfected with the same plasmid without a cDNA insert. Despite their slower growth, thymidine incorporation in response to thrombin is greater in transfected than in control cells. Thrombin-stimulated DNA synthesis is sensitive to inhibition by pertussis toxin and is 5-fold more sensitive to inhibition by pertussis toxin in transfected cells than in control cells. The changes are receptor-specific since the mitogenic response to platelet-derived growth factor is indistinguishable between control and transfected cells. These studies suggest that the alpha i subunit composition of the cell may have profound effects on its growth and its response to stimulation through a specific cell surface receptor.
Authors:
Z Cui; M Zubiaur; D B Bloch; T Michel; J G Seidman; E J Neer
Related Documents :
18160936 - Differential and opposed transcriptional effects of interleukin-18 gene polymorphisms (...
2766456 - Expression of mammalian o6-alkylguanine-dna alkyltransferase in a cell line sensitive t...
16364466 - Co-transfection with the osteogenic protein (op)-1 gene and the insulin-like growth fac...
10037466 - Down-regulation of the expression of o-acetyl-gd3 by the o-acetylesterase cdna in hamst...
19896886 - Bidirectional extracellular matrix signaling during tissue morphogenesis.
23347136 - Antitumor efficacy on glioma models of pha-848125, a multikinase inhibitor able to cros...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  266     ISSN:  0021-9258     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  1991 Oct 
Date Detail:
Created Date:  1991-12-02     Completed Date:  1991-12-02     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  20276-82     Citation Subset:  IM    
Affiliation:
Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
3T3 Cells / drug effects
Adenylate Cyclase / metabolism
Animals
Blotting, Western
Cell Cycle / drug effects
DNA / biosynthesis,  drug effects,  genetics
Electrophoresis, Gel, Two-Dimensional
GTP-Binding Proteins / genetics*,  metabolism
Genetic Vectors
Guanosine 5'-O-(3-Thiotriphosphate) / pharmacology
Mice
Mice, Inbred BALB C
Mitogens*
Pertussis Toxin
Platelet-Derived Growth Factor / pharmacology
Thrombin / pharmacology
Transfection
Virulence Factors, Bordetella / pharmacology
Grant Support
ID/Acronym/Agency:
CA 46361/CA/NCI NIH HHS; GM 36295/GM/NIGMS NIH HHS
Chemical
Reg. No./Substance:
0/Mitogens; 0/Platelet-Derived Growth Factor; 0/Virulence Factors, Bordetella; 37589-80-3/Guanosine 5'-O-(3-Thiotriphosphate); 9007-49-2/DNA; EC 2.4.2.31/Pertussis Toxin; EC 3.4.21.5/Thrombin; EC 3.6.1.-/GTP-Binding Proteins; EC 4.6.1.1/Adenylate Cyclase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Structural characterization of the asparagine-linked oligosaccharides from Trypanosoma brucei type I...
Next Document:  Mitochondrial creatine kinase mediates contact formation between mitochondrial membranes.