The type I Hsp40 zinc finger-like region is required for Hsp70 to capture non-native polypeptides from Ydj1
The type I Hsp40 zinc finger-like region is required for Hsp70 to capture non-native polypeptides from Ydj1
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DOI：
10.1074/jbc.m410645200
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发表时间：
2005-01-07
影响因子：
4.8
通讯作者：
Cyr, DM
中科院分区：
文献类型：
--
作者：
Fan, CY;Ren, HY;Cyr, DM
胞质酵母Hsp40 Ydj1含有一个保守的锌指样区（ZFLR），它有两个锌结合结构域（ZBD），有助于调节和指定Hsp70的功能。为了研究Ydj1 ZFLR作用的机制，构建并表征了ZBDI和ZBDII突变体。ZBDII突变体表现出对温度敏感的生长缺陷，但酵母耐受ZBDI的突变。然而，ZBDI和ZBDII突变体在促进雄激素受体（AR）折叠方面存在缺陷。AR折叠缺陷与AR和Ydj1 ZFLR突变体之间复合物的积累以及Hsp70.AR复合物形成的减少有关。纯化的Ydj1 ZBDI和ZBDII突变体可以结合非天然多肽，但不能将荧光素酶递送至Hsp70，并且在荧光素酶重折叠方面有缺陷。有趣的是，Ydj1协同Hsp70抑制热诱导蛋白聚集的能力被ZBDII的突变阻断，但ZBDI没有。因此，ZBDII是酵母在热应激中生存所必需的，因为Ydj1与Hsp70合作抑制蛋白质聚集是必需的。另一方面，蛋白质折叠依赖于ZBDI和ZBDII的作用，因为Hsp70从Ydj1捕获非天然多肽需要ZBDI和ZBDII。
The cytosolic yeast Hsp40 Ydj1 contains a conserved zinc finger-like region (ZFLR), which has two zinc-binding domains (ZBD), that helps regulate and specify Hsp70 function. To investigate the mechanism for Ydj1 ZFLR action, ZBDI and ZBDII mutants were constructed and characterized. ZBDII mutants exhibited temperature-sensitive growth defects, but yeast tolerated mutation of ZBDI. However, ZBDI and ZBDII mutants were defective at facilitating androgen receptor (AR) folding. Defective AR folding was associated with the accumulation of complexes between AR and Ydj1 ZFLR mutants and a reduction in Hsp70.AR complex formation. Purified Ydj1 ZBDI and ZBDII mutants could bind non-native polypeptides but could not deliver luciferase to Hsp70 and were defective at luciferase refolding. Interestingly, the ability of Ydj1 to synergize with Hsp70 to suppress thermally induced protein aggregation was blocked by mutation of ZBDII, but not ZBDI. Hence, ZBDII is required for yeast to survive heat stress because it is essential for Ydj1 to cooperate with Hsp70 to suppress protein aggregation. On the other hand, protein folding is dependent upon the action of both ZBDI and ZBDII because each is required for Hsp70 to capture non-native polypeptides from Ydj1.