Kothary R K, Jones D, Candido E P
Mol Cell Biol. 1984 Sep;4(9):1785-91. doi: 10.1128/mcb.4.9.1785-1791.1984.
RTG-2 cells, a line of fibroblasts from rainbow trout (Salmo gairdnerii), are induced to synthesize a distinct set of heat-shock polypeptides after exposure to elevated temperature or to low concentrations of sodium arsenite. We isolated and characterized two cDNA sequences, THS70.7 and THS70.14, encoding partial information for two distinct species of 70-kilodalton heat shock polypeptide (hsp70) from these cells. These sequences are identical at 73.3% of the nucleotide positions in their regions of overlap, and their degree of sequence conservation at the polypeptide level is 88.1%. The two derived trout hsp70 polypeptide sequences show extensive homology with derived amino acid sequences for hsp70 polypeptides from Drosophila melanogaster and Saccharomyces cerevisiae. Northern blot analysis of RNA from arsenite-induced RTG-2 cells, with the trout hsp70 cDNAs as probes, revealed the presence of three hsp70 mRNA species. Southern blot analysis of trout testis DNA cleaved with various restriction endonucleases revealed a small number of bands hybridizing to the hsp70 cDNAs, suggesting the existence of a small family of hsp70 genes in this species. Finally, trout hsp70 cDNA sequences cross-hybridized with restriction fragments in genomic DNA from HeLa cells, bovine liver, Caenorhabditis elegans, and D. melanogaster.
RTG - 2细胞系源自虹鳟鱼（Salmo gairdnerii）的成纤维细胞，在暴露于高温或低浓度亚砷酸钠后，会被诱导合成一组独特的热休克多肽。我们从这些细胞中分离并鉴定了两个cDNA序列，即THS70.7和THS70.14，它们编码了两种不同的70千道尔顿热休克多肽（hsp70）的部分信息。这些序列在重叠区域的核苷酸位置上有73.3%是相同的，在多肽水平上的序列保守程度为88.1%。这两个推导得到的虹鳟鱼hsp70多肽序列与黑腹果蝇和酿酒酵母的hsp70多肽的推导氨基酸序列显示出广泛的同源性。以虹鳟鱼hsp70 cDNA为探针，对亚砷酸钠诱导的RTG - 2细胞的RNA进行Northern印迹分析，结果显示存在三种hsp70 mRNA。用各种限制性内切酶切割虹鳟鱼睾丸DNA后进行Southern印迹分析，结果显示有少量条带与hsp70 cDNA杂交，这表明该物种中存在一个小的hsp70基因家族。最后，虹鳟鱼hsp70 cDNA序列与来自HeLa细胞、牛肝、秀丽隐杆线虫和黑腹果蝇的基因组DNA中的限制性片段发生交叉杂交。
