PC phosphorylation increases the ability of AFAP-110 to cross-link actin filaments. Academic Article uri icon

Overview

abstract

  • The actin filament-associated protein and Src-binding partner, AFAP-110, is an adaptor protein that links signaling molecules to actin filaments. AFAP-110 binds actin filaments directly and multimerizes through a leucine zipper motif. Cellular signals downstream of Src(527F) can regulate multimerization. Here, we determined recombinant AFAP-110 (rAFAP-110)-bound actin filaments cooperatively, through a lateral association. We demonstrate rAFAP-110 has the capability to cross-link actin filaments, and this ability is dependent on the integrity of the carboxy terminal actin binding domain. Deletion of the leucine zipper motif or PKC phosphorylation affected AFAP-110's conformation, which correlated with changes in multimerization and increased the capability of rAFAP-110 to cross-link actin filaments. AFAP-110 is both a substrate and binding partner of PKC. On PKC activation, stress filament organization is lost, motility structures form, and AFAP-110 colocalizes strongly with motility structures. Expression of a deletion mutant of AFAP-110 that is unable to bind PKC blocked the effect of PMA on actin filaments. We hypothesize that upon PKC activation, AFAP-110 can be cooperatively recruited to newly forming actin filaments, like those that exist in cell motility structures, and that PKC phosphorylation effects a conformational change that may enable AFAP-110 to promote actin filament cross-linking at the cell membrane.

publication date

  • July 1, 2002

Research

keywords

  • Actins
  • Microfilament Proteins
  • Phosphoproteins
  • Protein Kinase C

Identity

PubMed Central ID

  • PMC117315

Scopus Document Identifier

  • 0036323671

Digital Object Identifier (DOI)

  • 10.1091/mbc.e01-12-0148

PubMed ID

  • 12134071

Additional Document Info

volume

  • 13

issue

  • 7