ASF1A regulates H4Y72 phosphorylation and promotes autophagy in colon cancer cells via a kinase activity

Abstract

Colon cancer is one of the most malignant cancers. Histone modification is closely related to tumour development. Our study explored the functions of anti-silencing function 1A (ASF1A) on H4Y72ph in colon cancer cells. Colon cancer cell lines and clinical specimens were obtained and/or transfected with full length ASF1A or interference mRNA to mimic or silence of ASF1A expression. Immunoprecipitation and GST pull down was used to target targeting ASF1A or H4Y72ph. Cells were transfected with H4WT- or H4Y72F-expressing. An in vitro kinase activity assay was set to determine whether ASF1A could phosphorylate H4. The severity of autophagy was measured by detecting number of autophagosomes, number of EGFP-LC3, LC3-II/I, percentage of degradation and expression of autophagy associated gene (ATG). ASF1A positively regulated H4Y72ph; Immunoprecipitation assay and GST pull down results showed that ASF1A interacted directly with H4. In addition, ASF1A silence inhibited autophagosomes number, EGFP-LC3 number, LC3-II/I, percentage of degradation and ATG expression. Moreover, H4Y72F impaired the promoting autophagy effects of ASF1A. The ASF1A-H4Y72ph axis promoted colon cancer autophagy via transcriptional regulation of ATG genes. ASF1A regulated H4Y72ph and promotes autophagy in colon cancer cells via a kinase activity through regulation of ATG.