Membrane-type 1 matrix metalloproteinase cytoplasmic tail binding protein-1 (MTCBP-1) acts as an eukaryotic aci-reductone dioxygenase (ARD) in the methionine salvage pathway
Membrane-type 1 matrix metalloproteinase cytoplasmic tail binding protein-1 (MTCBP-1) acts as an eukaryotic aci-reductone dioxygenase (ARD) in the methionine salvage pathway
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DOI：
10.1111/j.1365-2443.2005.00859.x
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发表时间：
2005-06-01
期刊：
影响因子：
2.1
通讯作者：
Seiki, M
中科院分区：
文献类型：
--
作者：
Hirano, W;Gotoh, I;Seiki, M
MTCBP-1被鉴定为结合膜型1基质金属蛋白酶（MT 1-MMP/MMP-14）的胞质尾区的蛋白质。由于MTCBP-1具有推定的β-桶结构，因此推测它是最近提出的cupin超家族的成员，该超家族尽管具有良好保守的β-桶结构，但包含非常多样化的蛋白质功能。MTCBP-1与cupin家族中的细菌酸-还原酮双加氧酶（ARD）显示出显著的同源性，cupin家族是甲硫氨酸补救途径（MTA循环）中的酶。由于很难推测cupin蛋白质的功能，简单地基于它们的序列同源性，我们检查是否真核ARD同源物肯定在甲硫氨酸代谢中发挥作用。在贫硫条件下，提供MTA循环的底物时，酵母可以生长。酵母ARD同源物YMR 009 w基因的破坏消除了细胞在这种培养条件下生长的能力。YMR 009 w或MTCBP-1基因的再表达恢复了细胞生长。突变分析显示，β-桶折叠中的谷氨酸残基和β-桶折叠的N-末端延伸对于恢复生长的活性是重要的。因此，作为MT 1-MMP的结合蛋白分离的MTCBP-1被证明在酵母中的MTA循环中作为ARD样酶起作用。
MTCBP-1 was identified as a protein that binds the cytoplasmic tail of membrane-type 1 matrix metalloproteinase (MT1-MMP/MMP-14). Since MTCBP-1 has a putative beta-barrel structure, it is presumably a member of the recently proposed cupin superfamily that contains tremendously diverged functions of proteins in spite of their well-conserved beta-barrel structure. MTCBP-1 shows significant homology to the bacterial aci-reductone dioxygenase (ARD) in the cupin family, which is an enzyme in the methionine salvage pathway (MTA cycle). Since it is difficult to speculate the functions of cupin proteins simply based on their sequence homology, we examined whether the eukaryotic ARD homologs surely function in the methionine metabolism. Under sulfur-depleted conditions, yeast could grow when substrate of MTA cycle was provided. Disruption of the yeast ARD homolog, YMR009w gene, abolished ability of the cells to grow in this culture condition. Re-expression of either the YMR009w or MTCBP-1 gene restored the cell growth. Mutation analysis revealed that the glutamic acid residue in the beta-barrel fold and the N-terminal extension from the beta-barrel fold were found to be important for the activity to restore the growth. Thus, MTCBP-1 isolated as a binding protein for MT1-MMP was demonstrated to function as an ARD-like enzyme in the MTA cycle in yeast.