Polyphosphoinositides Inhibit the Interaction of Vinculin with Actin Filaments
Binding of vinculin to adhesion plaque proteins is restricted by an intramolecular association of vinculinâs head and tail regions. Results of previous work suggest that polyphosphoinositides disrupt this interaction and thereby promote binding of vinculin to both talin and actin. However, data pr...
Saved in:
Published in | The Journal of biological chemistry Vol. 274; no. 26; pp. 18414 - 18420 |
---|---|
Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Biochemistry and Molecular Biology
25.06.1999
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Binding of vinculin to adhesion plaque proteins is restricted by an intramolecular association of vinculinâs head and tail
regions. Results of previous work suggest that polyphosphoinositides disrupt this interaction and thereby promote binding
of vinculin to both talin and actin. However, data presented here show that phosphatidylinositol 4,5-bisphosphate (PI4,5P 2 ) inhibits the interaction of purified tail domain with F-actin. Upon re-examining the effect of PI4,5P 2 on the actin and talin-binding activities of intact vinculin, we find that when the experimental design controls for the
effect of magnesium on aggregation of PI4,5P 2 micelles, polyphosphoinositides promote interactions with the talin-binding domain, but block interactions of the actin-binding
domain. In contrast, if vinculin is trapped in an open confirmation by a peptide specific for the talin-binding domain of
vinculin, actin binding is allowed. These results demonstrate that activation of the actin-binding activity of vinculin requires
steps other than or in addition to the binding of PI4,5P 2 . |
---|---|
ISSN: | 0021-9258 1083-351X |
DOI: | 10.1074/jbc.274.26.18414 |