Linked Life Data

15387825

Source:http://linkedlifedata.com/resource/pubmed/id/15387825

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2004-9-24
pubmed:abstractText
The Frz chemosensory system controls directed motility in Myxococcus xanthus by regulating cellular reversal frequency. M. xanthus requires the Frz system for vegetative swarming on rich media and for cellular aggregation during fruiting body formation on starvation media. The Frz signal transduction pathway is formed by proteins that share homology with chemotaxis proteins from enteric bacteria, which are encoded in the frzA-F putative operon and the divergently transcribed frzZ gene. FrzCD, the Frz system chemoreceptor, contains a conserved C-terminal module present in methyl-accepting chemotaxis proteins (MCPs); but, in contrast to most MCPs, FrzCD is localized in the cytoplasm and the N-terminal region of FrzCD does not contain transmembrane or sensing domains, or even a linker region. Previous work on the Frz system was limited by the unavailability of deletion strains. To understand better how the Frz system functions, we generated a series of in-frame deletions in each of the frz genes as well as regions encoding the N-terminal portion of FrzCD. Analysis of mutants containing these deletions showed that FrzCD (MCP), FrzA (CheW) and FrzE (CheA-CheY) control vegetative swarming, responses to repellents and directed movement during development, thus constituting the core components of the Frz pathway. FrzB (CheW), FrzF (CheR), FrzG (CheB) and FrzZ (CheY-CheY) are required for some but not all responses. Furthermore, deletion of approximately 25 amino acids from either end of the conserved C-terminal region of FrzCD results in a constitutive signalling state of FrzCD, which induces hyper-reversals with no net cell movement. Surprisingly, deletion of the N-terminal region of FrzCD shows only minor defects in swarming. Thus, signal input to the Frz system must be sensed by the conserved C-terminal module of FrzCD and not the usual N-terminal region. These results indicate an alternative mechanism for signal sensing with this cytoplasmic MCP.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0950-382X
pubmed:author
pubmed:copyrightInfo
Copyright 2004 Blackwell Publishing Ltd
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1501-13
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Analysis of the Frz signal transduction system of Myxococcus xanthus shows the importance of the conserved C-terminal region of the cytoplasmic chemoreceptor FrzCD in sensing signals.
pubmed:affiliation
Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3204, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.