HEAT-SHOCK PROTEIN HSP70 PROTECTS CELLS FROM THERMAL-STRESS EVEN AFTER DELETION OF ITS ATP-BINDING DOMAIN
HEAT-SHOCK PROTEIN HSP70 PROTECTS CELLS FROM THERMAL-STRESS EVEN AFTER DELETION OF ITS ATP-BINDING DOMAIN
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DOI：
10.1073/pnas.89.6.2036
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发表时间：
1992-03-15
影响因子：
11.1
通讯作者：
LEE, WMF
中科院分区：
文献类型：
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作者：
LI, GC;LI, LG;LEE, WMF
逆转录病毒介导的基因转移实验表明，当稳定和组成性地表达克隆的人类基因编码完整的人类70 kda热休克蛋白（hsp70）时，啮齿动物细胞变得耐热。表达高水平hsp70蛋白的细胞通常能更好地耐受热应激，而表达两种突变hsp70编码基因中的任何一种的细胞，其中一种具有4碱基对外框。缺失和帧内缺失密码子438-618的缺失是热敏的。这些结果为hsp70的表达直接导致热耐受性提供了有力的证据。令人惊讶的是，表达人类基因缺失密码子120-428的突变体hsp70的细胞却具有耐热性。由于该突变体的缺失区域包含人类hsp70的atp结合结构域，因此该结构域在hsp70介导的细胞热应激保护中似乎是必不可少的。
Retroviral-mediated gene transfer experiments show that rodent cells become heat resistant when stably and constitutively expressing a cloned human gene encoding an intact human 70-kDa heat shock protein (hsp70). Cells expressing higher levels of the hsp70 protein generally tolerate thermal stress better, whereas cells expressing either of two mutated hsp70-encoding genes, one with a 4-base pair out-of-frame. deletion and one with an in-frame deletion of codons 438-618, are heat sensitive. These results provide strong evidence that expression of hsp70 leads directly to thermal tolerance. Surprisingly, cells expressing a mutant hsp70 of a human gene missing codons 120-428 are, nevertheless, heat resistant. Because the deleted region of this mutant contains the ATP-binding domain of human hsp70, this domain appears dispensable in the hsp70-mediated protection of cells from thermal stress.