Hirai Yuya, Domae Eisuke, Yoshikawa Yoshihiro, Tomonaga Keizo
Department of Biology, Osaka Dental University, 8-1, Kuzuha Hanazono-cho, Hirakata, Osaka 573-1121, Japan.
Department of Biochemistry, Osaka Dental University, 8-1, Kuzuha Hanazono-cho, Hirakata, Osaka 573-1121, Japan.
J Biochem. 2020 Jul 1;168(1):33-40. doi: 10.1093/jb/mvaa023.
The RNA helicase, DDX17 is a member of the DEAD-box protein family. DDX17 has two isoforms: p72 and p82. The p82 isoform has additional amino acid sequences called intrinsically disordered regions (IDRs), which are related to the formation of membraneless organelles (MLOs). Here, we reveal that p72 is mostly localized to the nucleoplasm, while p82 is localized to the nucleoplasm and nucleoli. Additionally, p82 exhibited slower intranuclear mobility than p72. Furthermore, the enzymatic mutants of both p72 and p82 accumulate into the stress granules. The enzymatic mutant of p82 abolishes nucleolar localization of p82. Our findings suggest the importance of IDRs and enzymatic activity of DEAD-box proteins in the intracellular distribution and formation of MLOs.
RNA解旋酶DDX17是DEAD-box蛋白家族的成员。DDX17有两种异构体：p72和p82。p82异构体具有额外的氨基酸序列，称为内在无序区域（IDR），其与无膜细胞器（MLO）的形成有关。在这里，我们发现p72主要定位于核质，而p82定位于核质和核仁。此外，p82在核内的移动速度比p72慢。此外，p72和p82的酶突变体都会积累到应激颗粒中。p82的酶突变体消除了p82的核仁定位。我们的研究结果表明，DEAD-box蛋白的IDR和酶活性在MLO的细胞内分布和形成中具有重要意义。
