Divergent Hsc70 binding properties of mitochondrial and cytosolic aspartate aminotransferase - Implications for their segregation to different cellular compartments

被引:15
作者
Artigues, A [1 ]
Crawford, DL [1 ]
Iriarte, A [1 ]
Martinez-Carrion, M [1 ]
机构
[1] Univ Missouri, Sch Biol Sci, Div Biochem & Mol Biol, Kansas City, MO 64110 USA
关键词
D O I
10.1074/jbc.273.50.33130
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Cytosolic Hsc70 discriminates between the homologous mitochondrial and cytosolic isozymes of aspartate aminotransferase, binding exclusively the mitochondrial form. By screening a library of synthetic peptides spanning the sequence of the mitochondrial enzyme, we have identified binding sites in this polypeptide that interact with Hsc70. These potential binding sites are scattered over the entire sequence and map to secondary structure elements, particularly the alpha-helix, that are partly exposed on the surface of the native protein. Several peptides corresponding to analogous positions in the cytosolic enzyme sequence do not bind to Hsc70. Phylogenetic analyses suggest that Hsc70 binding sequences have diverged as a consequence of biochemical specialization ensuring differential interaction of each isozyme with the cellular machinery in charge of protein folding and translocation.
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收藏
页码:33130 / 33134
页数:5
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