Formin DAAM1 Organizes Actin Filaments in the Cytoplasmic Nodal Actin NetworkReportar como inadecuado

Formin DAAM1 Organizes Actin Filaments in the Cytoplasmic Nodal Actin Network - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

A nodal cytoplasmic actin network underlies actin cytoplasm cohesion in the absence of stress fibers. We previously described such a network that forms upon Latrunculin A LatA treatment, in which formin DAAM1 was localized at these nodes. Knock down of DAAM1 reduced the mobility of actin nodes but the nodes remained. Here we have investigated DAAM1 containing nodes after LatA washout. DAAM1 was found to be distributed between the cytoplasm and the plasma membrane. The membrane binding likely occurs through an interaction with lipid rafts, but is not required for F-actin assembly. Interesting the forced interaction of DAAM1 with plasma membrane through a rapamycin-dependent linkage, enhanced F-actin assembly at the cell membrane compared to the cytoplasm after the LatA washout. However, immediately after addition of both rapamycin and LatA, the cytoplasmic actin nodes formed transiently, before DAAM1 moved to the membrane. This was consistent with the idea that DAAM1 was initially anchored to cytoplasmic actin nodes. Further, photoactivatable tracking of DAAM1 showed DAAM1 was immobilized at these actin nodes. Thus, we suggest that DAAM1 organizes actin filaments into a nodal complex, and such nodal complexes seed actin network recovery after actin depolymerization.

Autor: Weiwei Luo, Zi Zhao Lieu, Ed Manser, Alexander D. Bershadsky, Michael P. Sheetz



Documentos relacionados