Structure, expression, and evolution of a heat shock gene locus in Caenorhabditis elegans that is flanked by repetitive elements.
Structure, expression, and evolution of a heat shock gene locus in Caenorhabditis elegans that is flanked by repetitive elements.
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秀丽隐杆线虫热休克基因座的结构、表达和进化，该基因座两侧有重复元件。
DOI：
10.1016/s0021-9258(18)67194-7
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
E. Candido
中科院分区：
文献类型：
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作者：
D. Jones;R. Russnak;R. Kay;E. Candido
通过DNA序列测定，发现秀丽隐杆线虫中存在一个含有两个hsp 16基因的位点。每个基因编码一个16 kDa的多肽，该多肽在热诱导后表达。这两个基因，命名为hsp 16 -2和hsp 16 -41，排列方向不同，每个基因分别含有一个46和58个碱基对的内含子。虽然这两种基因转录本在体内有效地剪接，hsp 16 -41对应于先前分离的cDNA，其含有未剪接的内含子序列。这两个基因的5 '非编码区含有TATA盒，其前18或19个核苷酸上游是热休克调节序列。3 '-非编码区含有多聚腺苷酸化信号（AATAAA），其位于能够形成发夹的序列的下游（hsp 16 -2）或紧邻（hsp 16 -41）。这对hsp 16基因的侧翼是三个拷贝的大约200 bp的分散重复元件（在基因座的一侧上两个拷贝，在另一侧上一个拷贝），其在整个C. elegans基因组，并已被指定为CeRep-16。连同先前描述的数据（Russnak，R. H、和Escherdo，E. P. M.（1985）Mol. Cell. Biol.5，1268-1278），这里呈现的结果定义了四个不同的相关小热休克蛋白基因的家族。它们在两个基因座上以不同的转录对排列。hsp 16 -48/41基因编码一类143个氨基酸残基长的HSP 16，而hsp 16 -1/2基因编码另一类长2个氨基酸残基的HSP 16。因此，每个基因座编码两种主要类型的HSP 16。这两个基因座在许多方面不同，包括在一个基因座存在两个热休克蛋白基因的串联反向重复，而在另一个基因座存在重复元件。序列比较使我们能够提出一个方案的四个基因的进化，并揭示保守的功能，可能参与调控其转录，RNA加工，或翻译的非编码区。使用基因座特异性杂交探针，我们发现基因座hsp 16 -2/41的基因表达水平比基因座hsp 16 -1/48高约20-40倍。
A locus containing two hsp16 genes in Caenorhabditis elegans has been characterized by DNA sequencing. Each gene encodes a 16-kDa polypeptide which is expressed following heat induction. The two genes, designated hsp16-2 and hsp16-41, are arranged in divergent orientations, and each contains a single intron of 46 and 58 base pairs, respectively. Although both gene transcripts are spliced efficiently in vivo, hsp16-41 corresponds to a previously isolated cDNA which contains an unspliced intron sequence. The 5'-noncoding regions of both genes contain TATA boxes preceded 18 or 19 nucleotides upstream by a heat shock regulatory sequence. The 3'-noncoding regions contain polyadenylation signals (AATAAA) either downstream (hsp16-2) or immediately adjacent (hsp16-41) to a sequence capable of forming a hairpin. This pair of hsp16 genes is flanked by three copies of an approximately 200-bp dispersed repetitive element (two copies on one side and a single one on the other side of the locus) which occurs in at least 70 copies throughout the C. elegans genome, and has been designated CeRep-16. Together with data described previously (Russnak, R. H., and Candido, E. P. M. (1985) Mol. Cell. Biol. 5, 1268-1278), the results presented here define a family of four distinct, related small heat shock protein genes. These are arranged in divergently transcribed pairs at two loci. The hsp16-48/41 genes code for one class of HSP16, 143-amino acid residues long, while the hsp16-1/2 genes encode the other class, which is 2 amino acid residues longer. Thus each locus codes for the two major types of HSP16. The two loci differ in a number of respects, including the presence of a tandem inverted duplication of two heat shock protein genes at one locus, and of repetitive elements at the other. Sequence comparisons allow us to propose a scheme for the evolution of the four genes and reveal conserved features of noncoding regions which may be involved in the regulation of their transcription, RNA processing, or translation. Using locus-specific hybridization probes, we have found that the genes at locus hsp16-2/41 are expressed at levels approximately 20-40-fold higher than those at locus hsp16-1/48.