HIPK2 phosphorylates RUNX1 and EP300

HIPK2 can simultaneously phosphorylate RUNX1 and EP300 (p300) histone acetyltransferase bound to the RUNX1:CBFB complex. RUNX1 is phosphorylated by HIPK2 at serine residues S249, S273, and S276. EP300 is phosphorylated by HIPK2 at multiple serine and threonine residues that have not been thoroughly identified. HIPK2-mediated phosphorylation contributed to the activation of histone acetyltransferase activity of EP300 at RUNX1 target promoters (Aikawa et al. 2006, Wee et al. 2008).

HIPK2能够同时磷酸化结合于RUNX1:CBFB复合物上的RUNX1和EP300（p300）组蛋白乙酰转移酶。RUNX1在丝氨酸残基S249、S273和S276处被HIPK2磷酸化。EP300在多个尚未彻底确定的丝氨酸和苏氨酸残基处被HIPK2磷酸化。HIPK2介导的磷酸化作用促进了EP300在RUNX1靶标启动子处的组蛋白乙酰转移酶活性的激活（Aikawa等，2006年，Wee等，2008年）。