Dual Role of the Molybdenum Cofactor Biosynthesis Protein MOCS3 in tRNA Thiolation and Molybdenum Cofactor Biosynthesis in Humans
Dual Role of the Molybdenum Cofactor Biosynthesis Protein MOCS3 in tRNA Thiolation and Molybdenum Cofactor Biosynthesis in Humans
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DOI：
10.1074/jbc.m112.351429
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发表时间：
2012-05-18
影响因子：
4.8
通讯作者：
Leimkuehler, Silke
中科院分区：
文献类型：
--
作者：
Chowdhury, Mita Mullick;Dosche, Carsten;Leimkuehler, Silke
我们研究了涉及人体内过硫化物硫转移的两条途径，钼辅助因子生物合成和tRNA硫代化。对人类细胞的研究表明，两种途径共享双结构域蛋白MOCS3。MOCS3具有n端腺苷化结构域和c端罗丹斯样结构域。我们发现MOCS3通过腺苷化和随后的硫转移步骤激活MOCS2A和URM1，从而在每个蛋白的C端形成硫代羧酸基团。MOCS2A和URM1是含有高度保守的c端双甘氨酸基序的β -抓褶蛋白。研究MOCS2A和URM1末端甘氨酸与MOCS3的相互作用和细胞定位的作用。MOCS2A或URM1的c端甘氨酸缺失导致与MOCS3的相互作用丧失。构建增强的青色荧光蛋白和增强的黄色荧光蛋白融合体，并通过供体寿命的减少来确定荧光共振能量转移效率。细胞定位结果显示，MOCS2A和URM1的C端额外甘氨酸的延伸改变了MOCS3从细胞质到细胞核的定位。
We studied two pathways that involve the transfer of persulfide sulfur in humans, molybdenum cofactor biosynthesis and tRNA thiolation. Investigations using human cells showed that the two-domain protein MOCS3 is shared between both pathways. MOCS3 has an N-terminal adenylation domain and a C-terminal rhodanese-like domain. We showed that MOCS3 activates both MOCS2A and URM1 by adenylation and a subsequent sulfur transfer step for the formation of the thiocarboxylate group at the C terminus of each protein. MOCS2A and URM1 are beta-grasp fold proteins that contain a highly conserved C-terminal double glycine motif. The role of the terminal glycine of MOCS2A and URM1 was examined for the interaction and the cellular localization with MOCS3. Deletion of the C-terminal glycine of either MOCS2A or URM1 resulted in a loss of interaction with MOCS3. Enhanced cyan fluorescent protein and enhanced yellow fluorescent protein fusions of the proteins were constructed, and the fluorescence resonance energy transfer efficiency was determined by the decrease in the donor lifetime. The cellular localization results showed that extension of the C terminus with an additional glycine of MOCS2A and URM1 altered the localization of MOCS3 from the cytosol to the nucleus.