Affiliation:
1. Laboratoire Information Génétique et Développement, Institut de Génétique et Microbiologie, Unité de Recherche Associée CNRS 2225, Université Paris-Sud, 91405 Orsay Cedex,1and
2. Institut de Biochimie et Génétique et Cellulaires, Unité Propre de Recherche CNRS 9026, 33077 Bordeaux Cedex,2 France
Abstract
ABSTRACT
The multicopy suppressors of the
snf1
defect, Msn2p and Msn4p transcription factors (Msn2/4p), activate genes through the stress-responsive
cis
element (CCCCT) in response to various stresses. This
cis
element is also the target for repression by the cyclic AMP (cAMP)-signaling pathway. We analyzed the two-dimensional gel electrophoresis pattern of protein synthesis of the
msn2 msn4
double mutant and compared it with that of the wild-type strain during exponential growth phase and at the diauxic transition. Thirty-nine gene products (including those of
ALD3
,
GDH3
,
GLK1
,
GPP2
,
HSP104
,
HXK1
,
PGM2
,
SOD2
,
SSA3
,
SSA4
,
TKL2
,
TPS1
, and
YBR149W
) are dependent upon Msn2/4p for their induction at the diauxic transition. The expression of all these genes is repressed by cAMP. Thirty other genes identified during this study are still inducible in the mutant. A subset of these genes were found to be superinduced at the diauxic transition, and others were subject to cAMP repression (including
ACH1
,
ADH2
,
ALD6
,
ATP2
,
GPD1
,
ICL1
, and
KGD2
). We conclude from this analysis that Msn2/4p control a large number of genes induced at the diauxic transition but that other, as-yet-uncharacterized regulators, also contribute to this response. In addition, we show here that cAMP repression applies to both Msn2/4p-dependent and -independent control of gene expression at the diauxic shift. Furthermore, the fact that all the Msn2/4p gene targets are subject to cAMP repression suggests that these regulators could be targets for the cAMP-signaling pathway.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology