RIOK3促进了caspase-10对PAK2的酶解激活

RIOK3 Promotes the Cleavage-activation of Caspase-10 on PAK2

RIO3为非典型激酶RIO家族的成员之一,仅在多细胞真核生物中出现,为研究RIOK3蛋白的功能,以其作为诱饵蛋白对成人肝cDNA文库进行酵母双杂交筛选,得到其相互作用蛋白PAK2,并通过细胞内免疫共沉淀和免疫荧光共定位实验验证了该相互作用。实时定量PCR和免疫印迹检测结果显示,RIOK3能够在蛋白水平上降低PAK2表达量。通过CCK-8和细胞凋亡检测,发现二者共表达可以抑制增殖并促进凋亡,并且这一促凋亡效应可以被caspase-10的无酶活最短剪切本caspase-10G所抑制。实验结果显示,RIOK3可能促进了caspase-10对PAK2的酶解,在PAK2的酶解激活途径中发挥重要作用。

RIO3, a member of atypical protein kinase, is only discovered in muhicellular eukaryotes. The human liver cDNA library was screened with pDBLeu-RIOK3 as bait plasmid by yeast two-hybrid system and PAK2 was identified as a RIOK3 interactive protein. The interaction was confirmed by co-immunoprecipitation assays and immunofluorescent localization experiments. Results of real-time quantitative PCR and Western blot showed that RIOK3 can reduce the amount of PAK2 at protein expression level. CCK-8 and apoptosis detection experiment showed that co-expression of RIOK3 and PAK2 can inhibit cell proliferation and promote apoptosis, and the apoptotic effect can be inhibited by caspase-10G, which is the minimum isoform of caspase-10 and had no enzyme activity. The experimental results showed that RIOK3 may promote cleavage of caspase-10 on PAK2 and play an important role in the PAK2 cleavage-activation pathway.