TY - JOUR
T1 - The structure of the macrophage actin skeleton.
AU - Yin, H. L.
AU - Hartwig, J. H.
PY - 1988
Y1 - 1988
N2 - The actin skeleton of the macrophage consists of a three-dimensional network of actin filaments and associated proteins. The organization of this multiprotein structure is regulated at several levels in cells. Receptor stimulation induces a massive actin polymerization at the cell cortex, changes in cell shape and active cellular movements. Gelsolin may have a pivotal role in restructuring the actin skeleton in response to agonist stimulation, as the activity of this potent actin-modulating protein is regulated by both Ca2+ and polyphosphoinositides. Micromolar concentrations of Ca2+ activate gelsolin to bind to the sides of actin filaments, sever, and cap the filament end. Polyphosphoinositides, in particular PIP and PIP2, release gelsolin from the filament ends. A structure-function analysis of gelsolin indicates that its N-terminal half is primarily responsible for severing actin filaments, and elucidates mechanisms by which Ca2+ and phospholipid may regulate gelsolin functions. The ultrastructure of actin filaments in the macrophage cortical cytoplasm is regulated, to a large extent, by the actin cross-linking protein, actin-binding protein (ABP) which defines filament orthogonality.
AB - The actin skeleton of the macrophage consists of a three-dimensional network of actin filaments and associated proteins. The organization of this multiprotein structure is regulated at several levels in cells. Receptor stimulation induces a massive actin polymerization at the cell cortex, changes in cell shape and active cellular movements. Gelsolin may have a pivotal role in restructuring the actin skeleton in response to agonist stimulation, as the activity of this potent actin-modulating protein is regulated by both Ca2+ and polyphosphoinositides. Micromolar concentrations of Ca2+ activate gelsolin to bind to the sides of actin filaments, sever, and cap the filament end. Polyphosphoinositides, in particular PIP and PIP2, release gelsolin from the filament ends. A structure-function analysis of gelsolin indicates that its N-terminal half is primarily responsible for severing actin filaments, and elucidates mechanisms by which Ca2+ and phospholipid may regulate gelsolin functions. The ultrastructure of actin filaments in the macrophage cortical cytoplasm is regulated, to a large extent, by the actin cross-linking protein, actin-binding protein (ABP) which defines filament orthogonality.
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M3 - Review article
C2 - 2855803
AN - SCOPUS:0024155176
SN - 0269-3518
VL - 9
SP - 169
EP - 184
JO - Journal of cell science. Supplement
JF - Journal of cell science. Supplement
ER -