help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Premont, R. T.
Right arrow Articles by Iyengar, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Premont, R. T.
Right arrow Articles by Iyengar, R.

Endocrinology, Vol 125, 1151-1160, Copyright © 1989 by Endocrine Society

ARTICLES

Heterologous desensitization of the liver adenylyl cyclase: analysis of the role of G-proteins

RT Premont and R Iyengar
Department of Pharmacology, Mount Sinai School of Medicine, City University of New York, New York 10029.

Glucagon treatment of chick hepatocytes in primary culture results in a rapid 20-30% decrease in NaF-stimulated adenylyl cyclase activity. This heterologous desensitization is rapidly reversible upon removal of hormone from the culture medium. This decrease in NaF-stimulated adenylyl cyclase activity agrees well with the decrease in Gs activity, as assessed by reconstitution of the cyc- S49 cell adenylyl cyclase. Recovery from heterologous desensitization within 30 min results in restoration of Gs activity to control levels. No changes in Gs-alpha protein levels could be determined by immunoblotting using an alpha s- specific antiserum during heterologous desensitization. Similarly, no change in the beta gamma-subunits or Gi-alpha-subunits were detected by immunoblotting analysis using subunit-specific antisera. Pretreatment of cells with pertussis toxin did not block the onset of either heterologous or homologous desensitization, indicating the lack of involvement of Gi in glucagon-induced desensitization. cAMP-dependent phosphorylation of G-proteins does not account for heterologous desensitization, since none of the G-protein subunits appears to be phosphorylated even in vitro. However, Gs as the locus of change in heterologous desensitization was confirmed by the observation that addition of purified Gs to desensitized cell membranes results in enhancement of NaF-stimulated adenylyl cyclase activity. From these data we conclude that postreceptor heterologous desensitization in chick hepatocytes results from a reversible decrease in Gs activity in the cell surface membrane.


This article has been cited by other articles:


Home page
 Proc. Natl. Acad. Sci. USAHome page
Y. Chen, A. Harry, J. Li, M. J. Smit, X. Bai, R. Magnusson, J. P. Pieroni, G. Weng, and R. Iyengar
Adenylyl cyclase 6 is selectively regulated by protein kinase A phosphorylation in a region involved in Galpha s stimulation
PNAS, December 9, 1997; 94(25): 14100 - 14104.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
G. Iwami, J.-i. Kawabe, T. Ebina, P. J. Cannon, C. J. Homcy, and Y. Ishikawa
Regulation of Adenylyl Cyclase by Protein Kinase A
J. Biol. Chem., May 26, 1995; 270(21): 12481 - 12484.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1989 by The Endocrine Society