Caulobacter is a single-celled organism which differentiates during its normal cell cycle. This differentiation provides well-defined landmarks which mark progression through the cell cycle. Consequently, Caulobacter is an excellent model system for studies on the control of cell cycle events. Since its differentiation occurs under constant environmental conditions in the absence of cell-cell interactions, Caulobacter must have some kind of internal clock responsible for the timing of cell cycle events. At present, the investigator's hypothesis is that part of the """"""""clock"""""""" comes from the ability of Caulobacter to monitor its progress through checkpoints in the cell cycle by using a series of membrane-bound senior proteins. Each sensor protein would change its conformation in response to the completion of a particular cell cycle event. The conformational change would result in the autophosphorylation of the sensor with the subsequent transfer of the phosphate group to the corresponding response regulator. To test this hypothesis, Dr. Ely proposes to determine when during the cell cycle the pleC gene is expressed; to determine the cellular location of the PleC protein; to determine how the expression of the pleC gene is regulated; to identify genes involved in polar organelle development which are regulated by the PleC sensor protein; to identify the response regulator(s) which work with PleC to regulate genes involved in polar organelle development, and to identify and characterize other phosphoproteins which regulate cell cycle-dependent gene expression in Caulobacter.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM050547-02
Application #
2188459
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1994-09-30
Project End
1998-08-31
Budget Start
1995-09-01
Budget End
1996-08-31
Support Year
2
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of South Carolina at Columbia
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
111310249
City
Columbia
State
SC
Country
United States
Zip Code
29208
Crymes Jr, W B; Zhang, D; Ely, B (1999) Regulation of podJ expression during the Caulobacter crescentus cell cycle. J Bacteriol 181:3967-73
Mangan, E K; Malakooti, J; Caballero, A et al. (1999) FlbT couples flagellum assembly to gene expression in Caulobacter crescentus. J Bacteriol 181:6160-70
Leclerc, G; Wang, S P; Ely, B (1998) A new class of Caulobacter crescentus flagellar genes. J Bacteriol 180:5010-9
Mullin, D A; Zies, D L; Mullin, A H et al. (1997) Genetic organization and transposition properties of IS511. Mol Gen Genet 254:456-63
Malakooti, J; Ely, B (1995) Principal sigma subunit of the Caulobacter crescentus RNA polymerase. J Bacteriol 177:6854-60
Malakooti, J; Wang, S P; Ely, B (1995) A consensus promoter sequence for Caulobacter crescentus genes involved in biosynthetic and housekeeping functions. J Bacteriol 177:4372-6