Linked Life Data

8221900

Source:http://linkedlifedata.com/resource/pubmed/id/8221900

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1993-12-10
pubmed:abstractText
The actin-bundling protein fimbrin is homologous to 1-plastin, a 65kD phosphoprotein expressed in leukocytes and transformed cells [de Arruda et al., J. Cell Biol. 111, 1069-1080]. Because fimbrin is present in cell adhesion sites, we studied the phosphorylation state of fimbrin and its distribution in macrophages sequentially extracted with Triton-X-100 (soluble fraction), Tween 40-deoxy-cholate (cytoskeletal fraction), and SDS (insoluble cytoskeletal fraction). The approximate distribution of fimbrin and actin among these fractions was found to be: 65% fimbrin/55% actin in the soluble fraction, 30% fimbrin/20% actin in the cytoskeletal fraction, and 5% fimbrin/25% actin in the insoluble cytoskeletal fraction. PMA did not alter this distribution. Fluorescence microscopy of acetone-extracted macrophages showed that actin is concentrated in podosomes at the substratum interface and is diffusely distributed throughout the remainder of the cell. Fimbrin colocalizes with actin in podosomes and also exhibits a punctate distribution in the cytoplasm that overlaps with actin. In Tween 40/DOC-extracted cells, podosomes remain, and fimbrin also exhibits a punctate distribution along actin filaments. Metabolic 32PO4 labeling revealed that fimbrin is constitutively phosphorylated and that phosphorylated fimbrin is concentrated in the insoluble cytoskeletal fraction. PMA increased the relative levels of fimbrin phosphorylation twofold but did not alter the pattern of fimbrin fluorescence or the distribution of phosphorylated fimbrin. Limited trypsin digestion and phosphoamino acid analysis demonstrated that phosphorylation occurs specifically on serine residues within the 10kD headpiece domain of fimbrin. Phosphorylation of the headpiece domain could regulate the actin binding and bundling properties of fimbrin, or it could regulate the interaction of fimbrin with other proteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0886-1544
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
223-33
pubmed:dateRevised
2008-9-3
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Fimbrin localized to an insoluble cytoskeletal fraction is constitutively phosphorylated on its headpiece domain in adherent macrophages.
pubmed:affiliation
Lab of Cancer Biology, Deaconess Hospital, Harvard Medical School, Boston, MA 02115.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't