Mortensen K, Larsson LI.Effects of cytochalasin D on the
actin cytoskeleton: association of neoformed actin aggregates
with proteins involved in signaling and endocytosis.
Cell Mol Life Sci. 2003 May;60(5):1007-12
Department of Cell Biology, Institute of Anatomy and
Physiology, The Royal Veterinary and Agricultural University,
Gronnegaardsvej 7, 1870 Frederiksberg C, Copenhagen, Denmark.
Cytochalasin D has been extensively used for assessing
the role of the actin cytoskeleton in different biological
processes. However, effects of Cytochalasin D have not
always been consistent and Cytochalasin D -treated cells have
been found to contain irregular spots of F-actin. By
transfecting MCF-7 cells with an actin-enhanced yellow
fluorescent protein fusion protein we show that, in vivo,
Cytochalasin D induces actin aggregation de novo, while
simultaneously depolymerizing preexisting actin cytoskeletal
components. We also show that Cytochalasin D -induced actin
aggregates bind the F-actin-selective drug phalloidin and
associate with proteins involved in cell signaling as well as
with receptors and endosomal markers (active MAP kinases,
paxillin, erbB2, transferrin, Rab-5), but not with clathrin,
protein kinase A, protein tyrosine phosphatase 1B, or tubulin.
Thus, Cytochalasin D induces new sites of actin
aggregation that selectively associate with several important
regulatory proteins. Failure of Cytochalasin D to interupt
a biological process may therefore not prove that the process is
independent of actin aggregation.
PMID: 12827288
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