The Activation of ARF1 Is Dynamically Regulated by its Palmitoylation.

ARF1 plays a crucial role in maintaining the structure and function of the Golgi apparatus, yet the precise on-site regulatory mechanism governing ARF1 activation remains incompletely understood. Here, we have uncovered a novel regulatory mechanism involving the palmitoylation of ARF1 at Cys159. Our findings in HEK293T cells demonstrate that ZDHHC8 is responsible for promoting ARF1 palmitoylation, while PPT2 is involved in the depalmitoylation of ARF1. Furthermore, our results indicate that mutation of Cys159 to Alanine abolishes ARF1 palmitoylation, leading to increased localization of ARF1 at the Golgi apparatus. Interestingly, we observed that upregulation of ARF1 palmitoylation by ZDHHC8 inhibits ARF1 activation, while downregulation of ARF1 palmitoylation through the expression of PPT2 or Cys159 to Alanine enhances ARF1 activation. Mechanistically, we propose that ARF1 palmitoylation plays a crucial role in regulating retrograde transport by interacting with key proteins such as β-COP and β-actin. Our study presents a model in which the activation of ARF1 is dynamically regulated by its palmitoylation status, shedding light on a previously unrecognized mechanism for controlling ARF1 function at the Golgi apparatus. These findings provide valuable insights into the regulatory pathways governing intracellular protein transport and cellular function.