Previous Article | Next Article ![]()
J. Bacteriol., 05 1995, 2663-2672, Vol 177, No. 10
MY Liu, H Yang and T Romeo
The carbon storage regulator gene, csrA, modulates the expression of genes
in the glycogen biosynthesis and gluconeogenesis pathways in Escherichia
coli and has been cloned, mapped and sequenced (T. Romeo, M. Gong, M.Y.
Liu, and A.M. Brun-Zinkernagel, J. Bacteriol. 175:4744- 4755, 1993; T.
Romeo and M. Gong, J. Bacteriol. 175:5740-5741, 1993). We have now
conducted experiments that begin to elucidate a unique mechanism for
csrA-mediated regulation. Steady-state levels of glgC transcripts, encoding
ADP-glucose pyrophosphorylase, were elevated by up to sixfold in a
csrA::kanR mutant and were less than 6.5% of wild- type levels in a strain
containing pCSR10 (csrA+), as shown by S1 nuclease protection analysis. The
rate of chemical decay of these transcripts after adding rifampin to
cultures was dramatically reduced by the csrA::kanR mutation. Deletion
studies of a glgC'-'lacZ translational fusion demonstrated that the region
surrounding the initiation codon was important for csrA-mediated regulation
and indicated that neither csrA-mediated regulation nor stationary phase
induction of glgC expression originates at the level of transcript
initiation. Cell-free (S-200) extracts containing the CsrA gene product
potently and specifically inhibited the in vitro transcription- translation
of glg genes. The deduced amino acid sequence of CsrA was found to contain
the KH motif, which characterizes a subset of diverse RNA-binding proteins.
The results indicate that CsrA accelerates net 5'- to-3' degradation of glg
transcripts, potentially through selective RNA binding.
Copyright © 1995, American Society for Microbiology
The product of the pleiotropic Escherichia coli gene csrA modulates glycogen biosynthesis via effects on mRNA stability
Department of Microbiology and Immunology, University of North Texas Health Science Center at Fort Worth 76107-2699, USA.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |