Characterization of the interaction between zyxin and members of the Ena/vasodilator-stimulated phosphoprotein family of proteins.
Zyxin contains a proline-rich N-terminal domain that is similar to the C-terminal domain in the ActA protein of the bacteria, Listeria monocytogenes. We screened the entire amino acid sequence of human zyxin for Mena-interacting peptides and found that, as with ActA, proline-rich sequences were the sole zyxin sequences capable of binding to Ena/vasodilator-stimulated phosphoprotein (VASP) family members in vitro. From this information, we tested zyxin mutants in which the proline-rich sequences were altered. The reduction in Mena/VASP binding was confirmed by peptide tests, immunoprecipitation, and ectopic expression of zyxin variants at the surface of mitochondria. By transfection assays we showed that zyxin interaction with Mena/VASP in vivo enhances the production of actin-rich structures at the apical surface of cells. Microinjection into cells of peptides corresponding to the first proline-rich sequence of zyxin caused the loss of Mena/VASP from focal contacts. Furthermore, these peptides reduced the degree of spreading of cells replated after trypsinization. We conclude that zyxin and proteins that harbor similar proline-rich repeats contribute to the positioning of Mena/VASP proteins. The positioning of Ena/VASP family members appears to be important when the actin cytoskeleton is reorganized, such as during spreading.
Drees
B
B
Huntsman Cancer Institute, Department of Biology, University of Utah, Salt Lake City, Utah 84103, USA.
Friederich
E
E
Fradelizi
J
J
Louvard
D
D
Beckerle
M C
MC
Golsteyn
R M
RM
D000595:Amino Acid Sequence; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D006023:Glycoproteins; D006801:Humans; D008089:Listeria monocytogenes; D008667:Metalloproteins / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D011392:Proline; D011485:Protein Binding; D060589:Zyxin; D000098662:Vasodilator-Stimulated Phosphoprotein
D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D006023:Glycoproteins; D008667:Metalloproteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; C092842:ZYX protein, human; D060589:Zyxin; D000098662:Vasodilator-Stimulated Phosphoprotein; D011392:Proline