Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2003-12-3
pubmed:abstractText
Cell polarization generally occurs along a single well-defined axis that is frequently determined by environmental cues such as chemoattractant gradients or cell-cell contacts, but polarization can also occur spontaneously in the apparent absence of such cues, through a process called symmetry breaking. In Saccharomyces cerevisiae, cells are born with positional landmarks that mark the poles of the cell and guide subsequent polarization and bud emergence to those sites, but cells lacking such landmarks polarize towards a random cortical site and proliferate normally. The landmarks employ a Ras-family GTPase, Rsr1p, to communicate with the conserved Rho-family GTPase Cdc42p, which is itself polarized and essential for cytoskeletal polarization. We found that yeast Cdc42p was effectively polarized to a single random cortical site even in the combined absence of landmarks, microtubules and microfilaments. Among a panel of Cdc42p effectors and interacting proteins, we found that the scaffold protein Bem1p was uniquely required for this symmetry-breaking behaviour. Moreover, polarization was dependent on GTP hydrolysis by Cdc42p, suggesting that assembly of a polarization site involves cycling of Cdc42p between GTP- and GDP-bound forms, rather than functioning as a simple on/off switch.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1465-7392
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1062-70
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Scaffold-mediated symmetry breaking by Cdc42p.
pubmed:affiliation
Department of Pharmacology and Cancer Biology Duke University Medical Center, Durham, NC 27710, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.