Altering membrane topology with Sar1 does not impair spindle assembly in Xenopus egg extracts.

ABSTRACT: Intracellular membrane networks including the endoplasmic reticulum (ER) and the Golgi apparatus experience dramatic reorganization upon entry into mitosis. However, the mechanisms driving these rearrangements and their importance for cell division are poorly understood. The GTPase Sar1 is a component of the secretory pathway and a key activator of anterograde transport of cargo from the ER to the Golgi. Here we show that Sar1 mutant proteins added to metaphase-arrested Xenopus laevis egg extracts cause dramatic effects on membrane organization. Live analysis of membrane structures in egg extract cytoplasm revealed a distinct network of sheets and tubules reflective of the organization of the ER in other systems. Addition of a constitutively active Sar1 GTPase mutant (H79G) increased membr

SUBMITTER: Riggs B 

PROVIDER: S-EPMC3661297 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature