Myosin, actin-binding protein (ABP) and gelsolin are proteins interacting with actin in vitro and may control the movement of amoeboid cells. The distribution of these proteins was examined by indirect immunofluorescence (IFL) of smeared, acetone-fixed lymphoid cells. Actin, ABP and gelsolin were found in filopodia and in the cytoplasm, whereas myosin was mainly in the cortical cytoplasm. In the presence of Ca2+ the staining of the filopodia by anti-actin, anti-ABP and anti-gelsolin antibodies were abolished. A 91 000 daltons (D) polypeptide reacting with anti-gelsolin antibodies and a 43 000 D polypeptide reacting with anti-actin antibodies were eluted from acetone-treated cells in presence of Ca2+. This effect of Ca2+ on the staining could be due to the action of gelsolin, which severs actin filaments. The shortened filaments would then elute from the cells during the staining procedures.
ASJC Scopus subject areas
- Cell Biology