Linked Life Data

8647830

Source:http://linkedlifedata.com/resource/pubmed/id/8647830

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
1996-7-22
pubmed:abstractText
Profilin, an essential G-actin-binding protein, has two opposite regulatory functions in actin filament assembly. It facilitates assembly at the barbed ends by lowering the critical concentration (Pantaloni, D., and Carlier, M.-F. (1993) Cell 75, 1007-1014); in contrast it contributes to the pool of unassembled actin when barbed ends are capped. We proposed that the first of these functions required an input of energy. How profilin uses the ATP hydrolysis that accompanies actin polymerization and whether the acceleration of nucleotide exchange on G-actin by profilin participates in its function in filament assembly are the issues addressed here. We show that 1) profilin increases the treadmilling rate of actin filaments in the presence of Mg2+ ions; 2) when filaments are assembled from CaATP-actin, which polymerizes in a quasireversible fashion, profilin does not promote assembly at the barbed ends and has only a G-actin-sequestering function; 3) plant profilins do not accelerate nucleotide exchange on G-actin, yet they promote assembly at the barbed end. The enhancement of nucleotide exchange by profilin is therefore not involved in its promotion of actin assembly, and the productive growth of filaments from profilin-actin complex requires the coupling of ATP hydrolysis to profilin-actin assembly, a condition fulfilled by Mg-actin, and not by Ca-actin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12302-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Role of nucleotide exchange and hydrolysis in the function of profilin in action assembly.
pubmed:affiliation
Laboratoire d'Enzymologie, CNRS, 91198 Gif-sur-Yvette, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't