|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 111, Issue 21 3235-3244, Copyright © 1998 by Company of Biologists
JOURNAL ARTICLES |
KM Gillen, M Pausch and HG Dohlman
Department of Pharmacology, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut 06536-0812, USA.
G proteins play a central role in transmitting signals from cell surface receptors to effector proteins inside the cell. Signaling can only occur, however, if all these protein components are properly assembled and localized at the plasma membrane. Past studies have shown that certain segments within the N-terminal region of the G protein alpha subunit are necessary for membrane attachment. Here we identify a region within the yeast G alpha (Gpa1) that is sufficient for membrane attachment, as well as for specific targeting to the plasma membrane. Initially, we constructed chimeric proteins that replace the N terminus of mammalian Gsalpha with the corresponding sequence from Gpa1. Gsalpha is inefficiently targeted to the yeast plasma membrane and therefore cannot fully complement the loss of Gpa1. Gpa1-Gsaplha chimeras were assayed for proper membrane localization by functional complementation of a gpa1Delta ;) mutant, and by sucrose density gradient fractionation of cell membranes. Most of the chimeras tested, including one with only the N-terminal 7 amino acids from Gpa1, exhibited normal membrane targeting and complementing activity. We also fused various lengths of N-terminal Gpa1 sequence to glutathione-S-transferase (GST), a heterologous protein normally expressed in the cytoplasm. The first 67- 36- or 9-amino acids of Gpa1 were all sufficient to direct GST specifically to the plasma membrane in yeast. This analysis defines the extreme N terminus of Gpa1 as the primary determinant of proper membrane targeting, and represents an essential step towards isolating and identifying G protein-targeting proteins within the plasma membrane.
This article has been cited by other articles:
![]() |
T. Harashima and J. Heitman G{alpha} Subunit Gpa2 Recruits Kelch Repeat Subunits That Inhibit Receptor-G Protein Coupling during cAMP-induced Dimorphic Transitions in Saccharomyces cerevisiae Mol. Biol. Cell, October 1, 2005; 16(10): 4557 - 4571. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Blackwell, I. M. Halatek, H.-J. N. Kim, A. T. Ellicott, A. A. Obukhov, and D. E. Stone Effect of the Pheromone-Responsive G{alpha} and Phosphatase Proteins of Saccharomyces cerevisiae on the Subcellular Localization of the Fus3 Mitogen-Activated Protein Kinase Mol. Cell. Biol., February 15, 2003; 23(4): 1135 - 1150. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Peng and J. E. Hopper Gene activation by interaction of an inhibitor with a cytoplasmic signaling protein PNAS, June 25, 2002; 99(13): 8548 - 8553. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. S. Evanko, M. M. Thiyagarajan, and P. B. Wedegaertner Interaction with Gbeta gamma Is Required for Membrane Targeting and Palmitoylation of Galpha s and Galpha q J. Biol. Chem., January 14, 2000; 275(2): 1327 - 1336. [Abstract] [Full Text] [PDF] |
||||