Acetytation of ACAP4 regutates CCL18-elicited breast cancer cell migration and invasion

Tumor metastasis represents the main causes of cancer-related death.Our recent study showed that chemokine CCL18 secreted from tumor-associated macrophages regulates breast tumor metastasis,but the underlying mechanisms remain less clear.Here, we show that ARF6 GTPase-activating protein ACAP4 regulates CCL18-elicited breast cancer cell migration via the acetyltransferase PCAF-mediated acetylation.CCL18 stimulation elicited breast cancer cell migration and invasion via PCAF-dependent acetylation.ACAP4 physically interacts with PCAF and is a cognate substrate of PCAF during CCL18 stimulation.The acetylation site of ACAP4 by PCAF was mapped to Lys311 by mass spectrometric analyses.Importantly,dynamic acetylation of ACAP4 is essential for CCL18-induced breast cancer cell migration and invasion,as overexpression of the persistent acetylation-mimicking or nonacetylatable ACAP4 mutant blocked CCL18-elicited cell migration and invasion.Mechanistically,the acetylation of ACAP4 at Lys311 reduced the lipid-binding activity of ACAP4 to ensure a robust and dynamic cycling of ARF6-ACAP4 complex with plasma membrane in response to CCL18 stimulation.Thus,these results present a previously undefined mechanism by which CCL18-elicited acetylation of the PH domain controls dynamic interaction between ACAP4 and plasma membrane during breast cancer cell migration and invasion.