Vimentin intermediate filaments provide structural stability to the mammalian Golgi apparatus

Abstract

The Golgi apparatus comprises a connected ribbon of stacked cisternal membranes localized to the perinuclear region of most vertebrate cells. The position and morphology of this organelle depends upon interactions with microtubules and the actin cytoskeleton. In contrast, we know relatively little about the relationship of the Golgi apparatus with intermediate filaments. In this study we show that the Golgi is in close physical proximity to vimentin intermediate filaments (IFs) in cultured mouse and human cells. We also show that the trans-Golgi network coiled-coil protein GORAB can physically associate with IFs. Although loss of vimentin and/or GORAB does not have major effects upon Golgi morphology at steady-state, the Golgi undergoes more rapid disassembly upon chemical disruption with the drug brefeldin A, and slower reassembly upon drug washout, in vimentin knockout cells. Moreover, loss of vimentin causes reduced Golgi ribbon integrity when cells are cultured on high stiffness hydrogels, which is exacerbated by loss of GORAB. These results indicate that vimentin IFs contribute to the structural stability of the Golgi apparatus, and suggest a role for GORAB in this process.