McMullin T W, Hallberg R L
Zoology Department, Iowa State University, Ames 50011.
Mol Cell Biol. 1987 Dec;7(12):4414-23. doi: 10.1128/mcb.7.12.4414-4423.1987.
We have identified and purified a 58-kilodalton protein of Tetrahymena thermophila whose synthesis during heat shock parallels that of the major heat shock proteins. This protein, hsp58, was found in both non-heat-shocked as well as heat-shocked cells; however, its concentration in the cell increased approximately two- to threefold during heat shock. The majority of hsp58 in both non-heat-shocked and heat-shocked cells was found by both cell fractionation studies and immunocytochemical techniques to be mitochondrially associated. During heat shock, the additional hsp58 was found to selectively accumulate in mitochondria. Nondenatured hsp58 released from mitochondria of non-heat-shocked or heat-shocked cells sedimented in sucrose gradients as a 20S to 25S complex. We suggest that this protein may play a role in mitochondria analogous to the role the major heat shock proteins play in the nucleus and cytosol.
我们已经鉴定并纯化了嗜热四膜虫的一种58千道尔顿的蛋白质，其在热休克期间的合成与主要热休克蛋白的合成情况相似。这种蛋白质，即热休克蛋白58（hsp58），在未受热休克以及受热休克的细胞中均有发现；然而，其在细胞中的浓度在热休克期间增加了约两到三倍。通过细胞分级分离研究和免疫细胞化学技术发现，未受热休克和受热休克细胞中的大多数hsp58都与线粒体相关。在热休克期间，额外的hsp58被发现选择性地在线粒体中积累。从未受热休克或受热休克细胞的线粒体中释放出的未变性hsp58在蔗糖梯度中以20S到25S的复合物形式沉降。我们认为这种蛋白质可能在线粒体中发挥的作用类似于主要热休克蛋白在细胞核和细胞质中发挥的作用。
