KIF5B and Dynein regulate adhesion-dependent Golgi organization and microtubule acetylation

Cell-matrix adhesion regulates Golgi organization through Arf1-mediated dynein recruitment, maintaining its juxtanuclear localization. On loss of adhesion, Arf1 activation drops, causing loss of dynein, promoting differential disorganization of cis- vs trans-Golgi along microtubules. Golgi regulates microtubule nucleation and stability. In fibroblasts, acetylated tubulin levels drop on loss of adhesion, recovering on re-adhesion with time. Active Arf1 overexpression in preventing Golgi disorganization sustains microtubule acetylation, also seen in T24 bladder cancer cells. Active Arf1 binds KIF5B, recruiting it to the Golgi. KIF5B and dynein knockdown disorganize the Golgi as ministacks, with cis- and trans-Golgi. Dynein knockdown disrupts MTOC positioning, causing ministacks to disperse, preventing Golgi reorganization upon re-adhesion. Dispersed ministacks interestingly maintain microtubule acetylation in adherent and non-adherent cells. The joint KIF5B-dynein knockdown causes the Golgi to lose its ribbon morphology, becoming compact while keeping cis- and trans-Golgi together. This also causes a change in spreading, aspect ratio and migration of knockdown cells, which could be regulated by their Golgi phenotype. In evaluating adhesion-dependent Golgi organization, we reveal the Arf1-KIF5B-dynein crosstalk to regulate Golgi-dependent tubulin acetylation and cell function.