KANK2 Links ?V?5 Focal Adhesions to Microtubules and Regulates Sensitivity to Microtubule Poisons and Cell Migration.

ABSTRACT: Integrins are heterodimeric glycoproteins that bind cells to extracellular matrix. Upon integrin clustering, multimolecular integrin adhesion complexes (IACs) are formed, creating links to the cell cytoskeleton. We have previously observed decreased cell migration and increased sensitivity to microtubule (MT) poisons, paclitaxel and vincristine, in the melanoma cell line MDA-MB-435S upon transfection with integrin ?V-specific siRNA, suggesting a link between adhesion and drug sensitivity. To elucidate the underlying mechanism, we determined ?V-dependent changes in IAC composition. Using mass spectrometry (MS)-based proteomics, we analyzed the components of isolated IACs of MDA-MB-435S cells and two MDA-MB-435S-derived integrin ?V-specific shRNA-expressing cell clones with decreased expression of integrin ?V. MS analysis showed that cells preferentially use integrin ?V?5 for the formation of IACs. The differential analysis between MDA-MB-435S cells and clones with decreased expression of integrin ?V identified key components of integrin ?V?5 adhesion complexes as talins 1 and 2, ?-actinins 1 and 4, filamins A and B, plectin and vinculin. The data also revealed decreased levels of several components of the cortical microtubule stabilization complex, which recruits MTs to adhesion sites (notably liprins ? and ?, ELKS, LL5?, MACF1, KANK1, and KANK2), following ?V knockdown. KANK2 knockdown in MDA-MB-435S cells mimicked the effect of integrin ?V knockdown and resulted in increased sensitivity to MT poisons and decreased migration. Taken together, we conclude that KANK2 is a key molecule linking integrin ?V?5 IACs to MTs, and enabling the actin-MT crosstalk that is important for both sensitivity to MT poisons and cell migration.

SUBMITTER: Paradzik M 

PROVIDER: S-EPMC7063070 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature