Linked Life Data

6894565

Source:http://linkedlifedata.com/resource/pubmed/id/6894565

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1981-8-20
pubmed:abstractText
We have studied the mechanism of Ca++-dependent restriction of actin filament length by villin, one of the major actin-associated proteins of intestinal microvilli microfilament bundles. Villin acts, even at a ratio of 1 to 1000 with respect to actin, very efficiently as a Ca++-dependent nucleation factor on actin assembly. This gives rise to unidirectional assembly, with the morphologically defined "barbed" end of the resulting filament being capped. Consequently, at steady state treadmilling of actin monomers through the filament is inhibited. Increase of the villin-to-actin ratio enhances the number of nucleated filaments necessarily shorter in length. This results finally in nonsedimentable F actin and a low molecular weight complex of one villin and three monomeric actins, which itself is a potent nucleator. Thus restriction of actin assembly by villin is not due to a direct inhibition of assembly but arises as the consequence of strongly enhanced nucleation followed by unidirectional elongation at the pointed end of the nucleated filaments. In addition, in the presence of Ca++-villin, but not the villin-actin complex, seems able to "break" or "sever" preformed F actin filaments. Thus a variety of cellular phenomena-nucleation, unidirectional assembly, filament end capping, nonpolymerizable actin and F actin bundles-can be observed in vitro in a two-protein component system modulated by the concentration of free Ca++.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0092-8674
pubmed:author
pubmed:issnType
Print
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
471-80
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
F actin assembly modulated by villin: Ca++-dependent nucleation and capping of the barbed end.
pubmed:publicationType
Journal Article