|Niwa, R., Nagata-Ohashi,
K., Takeichi, M., Mizuno, K. & Uemura, T. (2002) Control of actin
reorganization by slingshot, a family of phosphatases that
dephophorylate ADF/cofilin. Cell. 108, 233-246.
|The ADF (actin-depolymerizing
factor)/cofilin family is a stimulus-responsive mediator of actin
dynamics. In contrast to the mechanisms of inactivation of ADF/cofilin
by kinases such as LIM-kinase 1 (LIMK1), much less is known about its
reactivation through dephosphorylation. Here we report Slingshot (SSH),
a family of phosphatases that have the property of F actin binding. In
Drosophila, loss of ssh function dramatically increased levels of both F
actin and phospho-cofilin (P cofilin) and disorganized epidermal cell
morphogenesis. In mammalian cells, human SSH homologs (hSSHs) suppressed
LIMK1-induced actin reorganization. Furthermore, SSH and the hSSHs
dephosphorylated P cofilin in cultured cells and in cell-free assays.
Our results strongly suggest that the SSH family plays a pivotal role in
actin dynamics by reactivating ADF/cofilin in vivo.