Linked Life Data

21454476

Source:http://linkedlifedata.com/resource/pubmed/id/21454476

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
2011-5-9
pubmed:abstractText
Arp2/3 complex is a key actin filament nucleator that assembles branched actin networks in response to cellular signals. The activity of Arp2/3 complex is regulated by both activating and inhibitory proteins. Coronins make up a large class of actin-binding proteins previously shown to inhibit Arp2/3 complex. Although coronins are known to play a role in controlling actin dynamics in diverse processes, including endocytosis and cell motility, the precise mechanism by which they regulate Arp2/3 complex is unclear. We conducted a detailed biochemical analysis of budding yeast coronin, Crn1, and found that it not only inhibits Arp2/3 complex but also activates it. We mapped regions required for activation and found that Crn1 contains a sequence called CA, which is conserved in WASp/Scar proteins, the prototypical activators of Arp2/3 complex. Point mutations in CA abolished activation of Arp2/3 complex by Crn1 in vitro. Confocal microscopy and quantitative actin patch tracking showed that these mutants had defective endocytic actin patch dynamics in Saccharomyces cerevisiae, indicating that activation of Arp2/3 complex by coronin is required for normal actin dynamics in vivo. The switch between the dual modes of regulation by Crn1 is controlled by concentration, and low concentrations of Crn1 enhance filament binding by Arp2/3 complex, whereas high concentrations block binding. Our data support a direct tethering recruitment model for activation of Arp2/3 complex by Crn1 and suggest that Crn1 indirectly inhibits Arp2/3 complex by blocking it from binding actin filaments.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
13
pubmed:volume
286
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17039-46
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Mechanism of a concentration-dependent switch between activation and inhibition of Arp2/3 complex by coronin.
pubmed:affiliation
Institute of Molecular Biology and Department of Chemistry, University of Oregon, Eugene, Oregon 97403-1229, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural