Blumberg H, Silver P A
Department of Molecular Biology, Princeton University, New Jersey 08544.
Nature. 1991 Feb 14;349(6310):627-30. doi: 10.1038/349627a0.
Heat-shock proteins have been implicated in assembly of protein complexes, correct protein folding and uptake of proteins into organelles. In Escherichia coli, the heat-shock protein DnaJ and the Hsp70 homologue, DnaK, act together to disassemble a protein complex involved in bacteriophage lambda replication. We report the identification of SCJ1, a gene in the yeast Saccharomyces cerevisiae that encodes a homologue of the bacterial DnaJ protein. SCJ1 was identified by a genetic screen in which increased expression of candidate genes results in missorting of a nuclear-targeted test protein. The predicted amino-acid sequence of SCJ1 is 37% identical to the entire E. coli DnaJ protein. Hybridization experiments indicate that there is a family of yeast genes related to SCJ1. These findings suggest that the Hsp70 DnaK-DnaJ interaction is general to eukaryotes.
热休克蛋白与蛋白质复合物的组装、蛋白质的正确折叠以及蛋白质摄入细胞器的过程有关。在大肠杆菌中，热休克蛋白DnaJ和Hsp70同源物DnaK共同作用，拆解参与噬菌体λ复制的蛋白质复合物。我们报告了酵母酿酒酵母中一个名为SCJ1的基因的鉴定结果，该基因编码细菌DnaJ蛋白的同源物。SCJ1是通过基因筛选鉴定出来的，在该筛选中，候选基因表达的增加会导致核靶向测试蛋白的分选错误。SCJ1的预测氨基酸序列与整个大肠杆菌DnaJ蛋白有37%的同一性。杂交实验表明，存在一个与SCJ1相关的酵母基因家族。这些发现表明，Hsp70 DnaK - DnaJ相互作用在真核生物中是普遍存在的。
