Impacts of vimentin on centrosome functioning and microtubule dynamics.

Abstract

Cell migration is an important feature of migrating fibroblasts. For cell migration to occur, the cells must establish a polarity. The cytoskeletal filaments and the centrosome positioning play an important role in cell polarity. Intrinsically polarized microtubules are often associated with cell polarity. But recent studies show that loss of vimentin intermediate filaments (IF) leads to abnormally persistent cell migration in 3D microchannels. This result suggests vimentin also plays an important role in cell polarity. However, the interaction of vimentin IF with centrosome and microtubules to orchestrate cell polarity is unclear. To understand this, we investigate the effects of vimentin on the microtubule-nucleating activity of the cell centrosome and the dynamics of microtubule network using wild-type and vimentin-null mouse embryonic fibroblasts (mEFs). Our results indicate, the presence of vimentin impacts the structure of the centrosome by increasing the area of the centrosome marked by pericentriolar material (PCM) proteins. Vimentin also promotes microtubule regrowth after nocodazole washout assay and enhances the stability of microtubules by increasing the presence of acetylated (post translational modification) microtubules. Our findings give a new insight to the role of vimentin in cell polarity by modulating centrosome structure and functioning.