Molecular Biology of the Cell track citations

Home Help [Feedback] [For Subscribers] [Archive] [Search] --
QUICK SEARCH:   [advanced]


     

MBC in Press, published online ahead of print January 12, 2004
Mol. Biol. Cell 10.1091/mbc.E03-08-0622

A more recent version of this article appeared on March 1, 2004
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
E03-08-0622v1
15/3/1479    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
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 reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Saran, S.
Right arrow Articles by Schaap, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Saran, S.
Right arrow Articles by Schaap, P.

Submitted on August 25, 2003
Revised on November 19, 2003
Accepted on December 2, 2003

ADENYLYL CYCLASE G IS ACTIVATED BY AN INTRAMOLECULAR OSMOSENSOR

Shweta Saran1 and Pauline Schaap1*

1 School of Life Sciences, University of Dundee, UK

* Corresponding author. E-mail address: p.schaap{at}dundee.ac.uk.

Adenylyl cyclase G (ACG) is activated by high osmolality and mediates inhibition of spore germination by this stress factor. The catalytic domains of all eukaryote cyclases are active as dimers and dimerization often mediates activation. To investigate the role of dimerization in ACG activation, we coexpressed ACG with an ACG construct that lacked the catalytic domain (ACG{Delta}cat) and was driven by a UV-inducible promoter. After UV-induction of ACG{Delta}cat, cAMP production by ACG was strongly inhibited, but osmostimulation was not reduced. Size-fractionation of native ACG showed that dimers were formed between ACG molecules and between ACG and ACG{Delta}cat. However, high osmolality did not alter the dimer/monomer ratio. This indicates that ACG activity requires dimerization via a region outside the catalytic domain, but that dimer formation does not mediate activation. To establish whether ACG required auxiliary sensors for osmostimulation, we expressed ACG cDNA in a yeast adenylyl cyclase null mutant. In yeast, cAMP production by ACG was similarly activated by high osmolality as in Dictyostelium. This strongly suggests that the ACG osmosensor is intramolecular, which would define ACG as the first characterized primary osmosensor in eukaryotes.




This article has been cited by other articles:


Home page
 DevelopmentHome page
E. Alvarez-Curto, S. Saran, M. Meima, J. Zobel, C. Scott, and P. Schaap
cAMP production by adenylyl cyclase G induces prespore differentiation in Dictyostelium slugs
Development, March 1, 2007; 134(5): 959 - 966.
[Abstract] [Full Text] [PDF]


Home Help [Feedback] [For Subscribers] [Archive] [Search] --
Copyright © 2004 by The American Society for Cell Biology. Terms of copyright protection, warranties, and disclaimers.