Brown C R, Hong-Brown L Q, Doxsey S J, Welch W J
Department of Medicine, University of California, San Francisco 94143, USA.
J Biol Chem. 1996 Jan 12;271(2):833-40. doi: 10.1074/jbc.271.2.833.
In the accompanying paper (Brown, C. R., Doxsey, S. J., Hong-Brown, L. W., Martin, R. L., and Welch, W. J. (1996) J. Biol. Chem. 271, 824-832) two molecular chaperones, hsp 73 and TCP-1, were shown to be integral components of the centrosome. Here we show that heat shock treatment adversely affects both the structure and function of the centrosome, and that hsp 73 plays a role in the repair of the organelle. After heat shock treatment, the centrosome could not be identified via indirect immunofluorescence and cells were unable to support microtubule regrowth. During recovery from heat shock, a strong correlation between the return of staining of three centrosomal antigens (hsp 73, TCP-1, and pericentrin) and the recovery of microtubule regrowth properties was found. Incubation of cells with glycerol, a protein protective agent, prevented the heat induced alterations in the structure/function of the centrosome. Likewise, the recovery of the structure and function of the centrosome after heat shock treatment was significantly accelerated in cells first made thermotolerant. We provide evidence that this process is related to the levels of hsp 73 since: 1) microinjection of hsp 73 antibody blocked centrosomal reassembly and microtubule regrowth abilities following heat shock; and 2) microinjection of purified hsp 73 protein prior to heat shock treatment accelerated both the repair and function of the organelle, similar to that observed for thermotolerant cells.
在随附论文（Brown, C. R., Doxsey, S. J., Hong - Brown, L. W., Martin, R. L., and Welch, W. J. (1996) J. Biol. Chem. 271, 824 - 832）中，已表明两种分子伴侣hsp 73和TCP - 1是中心体的组成成分。在此我们表明热休克处理会对中心体的结构和功能产生不利影响，并且hsp 73在该细胞器的修复中发挥作用。热休克处理后，通过间接免疫荧光无法识别中心体，细胞也无法支持微管的重新生长。在从热休克恢复过程中，发现三种中心体抗原（hsp 73、TCP - 1和中心体蛋白）染色的恢复与微管重新生长特性的恢复之间存在很强的相关性。用蛋白质保护剂甘油孵育细胞可防止热诱导的中心体结构/功能改变。同样，在首先获得耐热性的细胞中，热休克处理后中心体结构和功能的恢复明显加速。我们提供证据表明该过程与hsp 73的水平有关，因为：1）热休克后显微注射hsp 73抗体可阻断中心体的重新组装和微管的重新生长能力；2）在热休克处理前显微注射纯化的hsp 73蛋白可加速该细胞器的修复和功能，这与在耐热细胞中观察到的情况相似。
