Abstract
Guinea pig hepatocytes fractionated by differential centrifugation into plasma membrane-enriched, microsomal, and cytosolic fractions were examined for their content of alpha and beta subunits of heterotrimeric GTP-binding proteins (G proteins) involved in signal transduction. alpha subunits of stimulatory (Gs) and inhibitory (Gi) proteins were detected by immunoblots with antisera reactive with the carboxyl-terminal decapeptide regions of these proteins. Unexpectedly, antisera (including immunopurified) to the alpha subunit but not the beta subunit reacted with a band of 100-kDa proteins in both the microsomal and cytosolic fractions. The immunoreactive 100-kDa proteins are not substrates for ADP-ribosylation catalyzed by pertussis toxin, cholera toxin, or diptheria toxin. Protease digests of the 100-kDa proteins yielded immunoreactive peptides that are distinctly different from those obtained from protease digests of alpha subunits of heterotrimeric G proteins. The 100-kDa protein(s) reactive with antisera to Gi alpha subunit bind to GTP-agarose but not to ATP-agarose. It is concluded that the immunoreactive 100-kDa proteins in microsomal and cytosolic fractions are structurally distinct G proteins from those linked to receptors in the plasma membrane and other G proteins such as elongation factor 2. Conceivably, the 100-kDa proteins represent a new class of G proteins.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Allende J. E., Seeds N. W., Conway T. W., Weissbach H. Guanosine triphosphate interaction with an amino acid polymerization factor from E. coli. Proc Natl Acad Sci U S A. 1967 Oct;58(4):1566–1573. doi: 10.1073/pnas.58.4.1566. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Berry M. N., Friend D. S. High-yield preparation of isolated rat liver parenchymal cells: a biochemical and fine structural study. J Cell Biol. 1969 Dec;43(3):506–520. doi: 10.1083/jcb.43.3.506. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
- Burgess G. M., McKinney J. S., Fabiato A., Leslie B. A., Putney J. W., Jr Calcium pools in saponin-permeabilized guinea pig hepatocytes. J Biol Chem. 1983 Dec 25;258(24):15336–15345. [PubMed] [Google Scholar]
- Carroll S. F., Collier R. J. Diphtheria toxin: quantification and assay. Methods Enzymol. 1988;165:218–225. doi: 10.1016/s0076-6879(88)65034-8. [DOI] [PubMed] [Google Scholar]
- Cleveland D. W., Fischer S. G., Kirschner M. W., Laemmli U. K. Peptide mapping by limited proteolysis in sodium dodecyl sulfate and analysis by gel electrophoresis. J Biol Chem. 1977 Feb 10;252(3):1102–1106. [PubMed] [Google Scholar]
- Fung B. K. Characterization of transducin from bovine retinal rod outer segments. I. Separation and reconstitution of the subunits. J Biol Chem. 1983 Sep 10;258(17):10495–10502. [PubMed] [Google Scholar]
- Gill D. L., Ghosh T. K., Mullaney J. M. Calcium signalling mechanisms in endoplasmic reticulum activated by inositol 1,4,5-trisphosphate and GTP. Cell Calcium. 1989 Jul;10(5):363–374. doi: 10.1016/0143-4160(89)90062-6. [DOI] [PubMed] [Google Scholar]
- Gilman A. G. G proteins: transducers of receptor-generated signals. Annu Rev Biochem. 1987;56:615–649. doi: 10.1146/annurev.bi.56.070187.003151. [DOI] [PubMed] [Google Scholar]
- Haraguchi K., Rodbell M. Isoproterenol stimulates shift of G proteins from plasma membrane to pinocytotic vesicles in rat adipocytes: a possible means of signal dissemination. Proc Natl Acad Sci U S A. 1990 Feb;87(3):1208–1212. doi: 10.1073/pnas.87.3.1208. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heyworth C. M., Whetton A. D., Wong S., Martin B. R., Houslay M. D. Insulin inhibits the cholera-toxin-catalysed ribosylation of a Mr-25000 protein in rat liver plasma membranes. Biochem J. 1985 Jun 15;228(3):593–603. doi: 10.1042/bj2280593. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hunkapiller M. W., Lujan E., Ostrander F., Hood L. E. Isolation of microgram quantities of proteins from polyacrylamide gels for amino acid sequence analysis. Methods Enzymol. 1983;91:227–236. doi: 10.1016/s0076-6879(83)91019-4. [DOI] [PubMed] [Google Scholar]
- Kanaho Y., Tsai S. C., Adamik R., Hewlett E. L., Moss J., Vaughan M. Rhodopsin-enhanced GTPase activity of the inhibitory GTP-binding protein of adenylate cyclase. J Biol Chem. 1984 Jun 25;259(12):7378–7381. [PubMed] [Google Scholar]
- Kohno K., Uchida T., Ohkubo H., Nakanishi S., Nakanishi T., Fukui T., Ohtsuka E., Ikehara M., Okada Y. Amino acid sequence of mammalian elongation factor 2 deduced from the cDNA sequence: homology with GTP-binding proteins. Proc Natl Acad Sci U S A. 1986 Jul;83(14):4978–4982. doi: 10.1073/pnas.83.14.4978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Merrick W. C., Kemper W. M., Kantor J. A., Anderson W. F. Purification and properties of rabbit reticulocyte protein synthesis elongation factor 2. J Biol Chem. 1975 Apr 10;250(7):2620–2625. [PubMed] [Google Scholar]
- Neer E. J., Pulsifer L., Wolf L. G. The amino terminus of G protein alpha subunits is required for interaction with beta gamma. J Biol Chem. 1988 Jun 25;263(18):8996–8970. [PubMed] [Google Scholar]
- Orci L., Malhotra V., Amherdt M., Serafini T., Rothman J. E. Dissection of a single round of vesicular transport: sequential intermediates for intercisternal movement in the Golgi stack. Cell. 1989 Feb 10;56(3):357–368. doi: 10.1016/0092-8674(89)90239-0. [DOI] [PubMed] [Google Scholar]
- Pfeuffer T. Guanine nucleotide-controlled interactions between components of adenylate cyclase. FEBS Lett. 1979 May 1;101(1):85–89. [PubMed] [Google Scholar]
- Péraldi S., Nguyen Than Dao B., Brabet P., Homburger V., Rouot B., Toutant M., Bouille C., Assenmacher I., Bockaert J., Gabrion J. Apical localization of the alpha subunit of GTP-binding protein Go in choroidal and ciliated ependymocytes. J Neurosci. 1989 Mar;9(3):806–814. doi: 10.1523/JNEUROSCI.09-03-00806.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ribeiro-Neto F., Mattera R., Grenet D., Sekura R. D., Birnbaumer L., Field J. B. Adenosine diphosphate ribosylation of G proteins by pertussis and cholera toxin in isolated membranes. Different requirements for and effects of guanine nucleotides and Mg2+. Mol Endocrinol. 1987 Jul;1(7):472–481. doi: 10.1210/mend-1-7-472. [DOI] [PubMed] [Google Scholar]
- Risser R. Abelson antigen is expressed on hematopoietic spleen colony-forming cells from mice carrying the Av-2S virus sensitivity gene. Proc Natl Acad Sci U S A. 1979 Oct;76(10):5350–5354. doi: 10.1073/pnas.76.10.5350. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rothman J. E., Orci L. Movement of proteins through the Golgi stack: a molecular dissection of vesicular transport. FASEB J. 1990 Mar;4(5):1460–1468. doi: 10.1096/fasebj.4.5.2407590. [DOI] [PubMed] [Google Scholar]
- Rotrosen D., Gallin J. I., Spiegel A. M., Malech H. L. Subcellular localization of Gi alpha in human neutrophils. J Biol Chem. 1988 Aug 5;263(22):10958–10964. [PubMed] [Google Scholar]
- Sefton B. M., Beemon K., Hunter T. Comparison of the expression of the src gene of Rous sarcoma virus in vitro and in vivo. J Virol. 1978 Dec;28(3):957–971. doi: 10.1128/jvi.28.3.957-971.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Seglen P. O. Preparation of rat liver cells. II. Effects of ions and chelators on tissue dispersion. Exp Cell Res. 1973 Jan;76(1):25–30. doi: 10.1016/0014-4827(73)90414-x. [DOI] [PubMed] [Google Scholar]
- Simonds W. F., Goldsmith P. K., Codina J., Unson C. G., Spiegel A. M. Gi2 mediates alpha 2-adrenergic inhibition of adenylyl cyclase in platelet membranes: in situ identification with G alpha C-terminal antibodies. Proc Natl Acad Sci U S A. 1989 Oct;86(20):7809–7813. doi: 10.1073/pnas.86.20.7809. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sullivan K. A., Liao Y. C., Alborzi A., Beiderman B., Chang F. H., Masters S. B., Levinson A. D., Bourne H. R. Inhibitory and stimulatory G proteins of adenylate cyclase: cDNA and amino acid sequences of the alpha chains. Proc Natl Acad Sci U S A. 1986 Sep;83(18):6687–6691. doi: 10.1073/pnas.83.18.6687. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tamir A., Gill D. M. ADP-ribosylation by cholera toxin of membranes derived from brain modifies the interaction of adenylate cyclase with guanine nucleotides and NaF. J Neurochem. 1988 Jun;50(6):1791–1797. doi: 10.1111/j.1471-4159.1988.tb02480.x. [DOI] [PubMed] [Google Scholar]
- Ueda T., Kikuchi A., Ohga N., Yamamoto J., Takai Y. GTPase activating proteins for the smg-21 GTP-binding protein having the same effector domain as the ras proteins in human platelets. Biochem Biophys Res Commun. 1989 Mar 31;159(3):1411–1419. doi: 10.1016/0006-291x(89)92267-5. [DOI] [PubMed] [Google Scholar]
- Ui M., Katada T., Murayama T., Kurose H., Yajima M., Tamura M., Nakamura T., Nogimori K. Islet-activating protein, pertussis toxin: a specific uncoupler of receptor-mediated inhibition of adenylate cyclase. Adv Cyclic Nucleotide Protein Phosphorylation Res. 1984;17:145–151. [PubMed] [Google Scholar]
- Van Dop C., Yamanaka G., Steinberg F., Sekura R. D., Manclark C. R., Stryer L., Bourne H. R. ADP-ribosylation of transducin by pertussis toxin blocks the light-stimulated hydrolysis of GTP and cGMP in retinal photoreceptors. J Biol Chem. 1984 Jan 10;259(1):23–26. [PubMed] [Google Scholar]
- Yamamoto K., Tanimoto T., Kim S., Kikuchi A., Takai Y. Small molecular weight GTP-binding proteins and signal transduction. Clin Chim Acta. 1989 Dec 15;185(3):347–355. doi: 10.1016/0009-8981(89)90225-8. [DOI] [PubMed] [Google Scholar]