Identification of three major sentrinization sites in PML
Identification of three major sentrinization sites in PML
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DOI：
10.1074/jbc.273.41.26675
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发表时间：
1998-10-09
影响因子：
4.8
通讯作者：
Yeh, ETH
中科院分区：
文献类型：
--
作者：
Kamitani, T;Kito, K;Yeh, ETH
急性早幼粒细胞白血病发生在染色体相互易位t（15;17）之后，其产生PML-视黄酸受体α融合蛋白（PML-RAR α）。我们先前已经表明野生型PML而不是PML-RAR α被泛素样蛋白的sentrin家族共价修饰（Kamitani，T.，阮氏H. P.，Kito，K.，Fukuda-Kamitani，T.，和Yeh，E. T. H.（1998）J.Biol.Chem.273，3117-3120）。为了理解PML与PML-RAR α的差异性sentrinization的潜在机制，进行了广泛的突变分析以确定哪些Lys残基是sentrinized的。我们发现，RING指结构域中的Lys（65）、B1盒中的Lys（160）和核定位信号中的Lys（490）贡献了三个主要的sentrinization位点。在所有三个位点中具有Lys至Arg取代的PML突变体正常表达，但不能被sentrinized。此外，三重置换突变体主要定位于核质，而野生型PML定位于核体。因此，在环指和BI盒的背景下，PML的sentrinization调节核体形成。此外，我们发现，PML-RAR α的sentrin化可以通过sentrin的过表达而恢复，但不能通过维甲酸处理。这些研究提供了新的见解急性早幼粒细胞白血病的病理生物化学和sentrin化途径。
Acute promyelocytic leukemia arises following a reciprocal chromosome translocation t(15;17), which generates PML-retinoic acid receptor alpha fusion proteins (PML-RAR alpha). We have shown previously that wild type PML, but not PML-RAR alpha, is covalently modified by the sentrin family of ubiquitin-like proteins (Kamitani, T., Nguyen, H. P., Kito, K., Fukuda-Kamitani, T., and Yeh, E. T. H. (1998) J. Biol. Chem. 273, 3117-3120). To understand the mechanisms underlying the differential sentrinization of PML versus PML-RAR alpha, extensive mutational analysis was carried out to determine which Lys residues are sentrinized, We show that Lys(65) in the RING finger domain, Lys(160) in the B1 Box, and Lys(490) in the nuclear localization signal contributes three major sentrinization sites. The PML mutant with Lys to Arg substitutions in all three sites is expressed normally, but cannot be sentrinized. Furthermore, the triple substitution mutant is localized predominantly to the nucleoplasm, in contrast to wild type PML, which is localized to the nuclear bodies. Thus, sentrinization of PML, in the context of the RING finger and the BI box, regulates nuclear body formation. Furthermore, we showed that sentrinization of PML-RAR alpha could be restored by overexpression of sentrin, but not by retinoic acid treatment. These studies provide novel insight into the pathobiochemistry of acute promyelocytic leukemia and the sentrinization pathway.