Although the analysis of gene regulation in prokaryotes has generally focused on understanding transcriptional control, the steady-state level of any given messenger RNA is a function of both synthesis and decay. Factors contributing to transcript stability thus must be important for gene regulation, particularly in Escherichia coli, since mRNA half-lives can vary more than 50 fold, from seconds to 30 minutes. While there has been considerable speculation regarding the mechanism of mRNA decay, until recently it has been difficult to study it. The goals of this project are to understand the molecular events involved in the turnover of mRNA in Escherichia coli and to examine its regulation. To do so, we will carry out a series of biochemical and genetic experiments to study proteins involved in mRNA decay and to characterize the products of new genes that are required for mRNA turnover and cell viability. We will focus on understanding the in vivo relationships and regulation of the mrsA (messenger RNA stability), mrsC, mrsF, and rne (RNase E) genes. Additionally, we will further characterize the catalytic activities of RNase E and try to identify the biochemical functions of the MrsA, MrsC and MrsF proteins. The MrsC protein is of particular interest because it is a homolog of a unique family of eukaryotic ATP-binding proteins. A more complete understanding of mRNA turnover in prokaryotes will provide an important model for studying eukaryotic message decay.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM028760-13
Application #
2175274
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1979-04-01
Project End
1998-03-31
Budget Start
1995-04-01
Budget End
1996-03-31
Support Year
13
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of Georgia
Department
Genetics
Type
Schools of Arts and Sciences
DUNS #
City
Athens
State
GA
Country
United States
Zip Code
30602
Ow, Maria C; Liu, Qi; Mohanty, Bijoy K et al. (2002) RNase E levels in Escherichia coli are controlled by a complex regulatory system that involves transcription of the rne gene from three promoters. Mol Microbiol 43:159-71
Mohanty, B K; Kushner, S R (2000) Polynucleotide phosphorylase, RNase II and RNase E play different roles in the in vivo modulation of polyadenylation in Escherichia coli. Mol Microbiol 36:982-94
Mohanty, B K; Kushner, S R (2000) Polynucleotide phosphorylase functions both as a 3' right-arrow 5' exonuclease and a poly(A) polymerase in Escherichia coli. Proc Natl Acad Sci U S A 97:11966-71
Ow, M C; Liu, Q; Kushner, S R (2000) Analysis of mRNA decay and rRNA processing in Escherichia coli in the absence of RNase E-based degradosome assembly. Mol Microbiol 38:854-66
Mohanty, B K; Kushner, S R (1999) Residual polyadenylation in poly(A) polymerase I (pcnB ) mutants of Escherichia coli does not result from the activity encoded by the f310 gene. Mol Microbiol 34:1109-19
Mohanty, B K; Kushner, S R (1999) Analysis of the function of Escherichia coli poly(A) polymerase I in RNA metabolism. Mol Microbiol 34:1094-108
Zhang, G; Deng, E; Baugh, L et al. (1998) Identification and characterization of Escherichia coli DNA helicase II mutants that exhibit increased unwinding efficiency. J Bacteriol 180:377-87
Wang, R F; O'Hara, E B; Aldea, M et al. (1998) Escherichia coli mrsC is an allele of hflB, encoding a membrane-associated ATPase and protease that is required for mRNA decay. J Bacteriol 180:1929-38
Granger, L L; O'Hara, E B; Wang, R F et al. (1998) The Escherichia coli mrsC gene is required for cell growth and mRNA decay. J Bacteriol 180:1920-8
Zhang, G; Deng, E; Baugh, L R et al. (1997) Conserved motifs II to VI of DNA helicase II from Escherichia coli are all required for biological activity. J Bacteriol 179:7544-50

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