QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wingrove, J A Articles by Gober, J W Search for Related Content PubMed PubMed Citation Articles by Wingrove, J A Articles by Gober, J W Social Bookmarking                   What's this?

Research Papers

A sigma 54 transcriptional activator also functions as a pole-specific repressor in Caulobacter.

Department of Chemistry and Biochemistry, University of California, Los Angeles 90024.

Abstract

The differential localization of proteins in the Caulobacter predivisional cell leads to the formation of two distinct progeny cells: a motile swarmer cell and a sessile stalked cell. Pole-specific transcription in the predivisional cell is one mechanism responsible for protein localization. Here we show that the sigma 54 transcriptional activator FlbD, which activates swarmer pole-specific transcription of a subset of late flagellar genes, is also capable of functioning as a pole-specific repressor of the early flagellar fliF operon. DNase I footprinting and methylation interference assays indicate that FlbD binds to regions of the fliF promoter at regions that would be likely to interfere with the binding of RNA polymerase. A mutation that abolishes FlbD binding results in up to a fourfold increase in fliF promoter expression. This mutation alters both the spatial and temporal pattern of fliF expression resulting in the inappropriate expression of the fliF operon in the swarmer pole of the predivisional cell. These results demonstrate that FlbD represses early flagellar gene expression in the swarmer pole of the Caulobacter predivisional cell. This is the first instance in which a protein specifically involved in pole-specific repression has been identified in Caulobacter. The restriction of FlbD activity to the swarmer pole accomplishes two regulatory missions by simultaneously activating late flagellar gene expression and repressing early flagellar genes.

CiteULike

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				R. E. Muir, J. Easter, and J. W. Gober The trans-acting flagellar regulatory proteins, FliX and FlbD, play a central role in linking flagellar biogenesis and cytokinesis in Caulobacter crescentus Microbiology, November 1, 2005; 151(11): 3699 - 3711. [Abstract] [Full Text] [PDF]

				R. E. Muir and J. W. Gober Role of Integration Host Factor in the Transcriptional Activation of Flagellar Gene Expression in Caulobacter crescentus J. Bacteriol., February 1, 2005; 187(3): 949 - 960. [Abstract] [Full Text] [PDF]

				C. H. Boyd and J. W. Gober Temporal Regulation of Genes Encoding the Flagellar Proximal Rod in Caulobacter crescentus J. Bacteriol., January 15, 2001; 183(2): 725 - 735. [Abstract] [Full Text]

				P. Genschik, K. Drabikowski, and W. Filipowicz Characterization of the Escherichia coli RNA 3'-Terminal Phosphate Cyclase and Its sigma 54-Regulated Operon J. Biol. Chem., September 25, 1998; 273(39): 25516 - 25526. [Abstract] [Full Text] [PDF]

				C. D. Mohr, J. K. MacKichan, and L. Shapiro A Membrane-Associated Protein, FliX, Is Required for an Early Step in Caulobacter Flagellar Assembly J. Bacteriol., April 15, 1998; 180(8): 2175 - 2185. [Abstract] [Full Text]

				J. A. Wingrove and J. W. Gober Identification of an Asymmetrically Localized Sensor Histidine Kinase Responsible for Temporally and Spatially Regulated Transcription Science, October 25, 1996; 274(5287): 597 - 601. [Abstract] [Full Text]