Structure and expression of a rice hsp70 gene

A genomic hsp70 gene was isolated from a rice IR36 genomic library and 4 794 bp of the gene have been sequenoed. The 5' flanking region of the gene contained a putative TATA box and a typical heat shock element sequence 5'-CTcgGAAccTTCgAG-3'. The amino acid sequence of the rice HSP70 deduced from the coding region shared 84%-92% homologies with those of HSP70s from other plant species. An intron 1939bp long was identified in the coding region at the codon specifying amino acid 72 (Asp), the similar position introns occurring in other intron-containing hsp70 genes. In addition, another intron of 57 bp was found in the 3'-untranslated region in the rice hsp70 gene. Southern blot hybridization showed that rice hsp70 gene family contained at least three members. Analysis of the RNA leveis with the gene-specific and non-specific probes revealed that the rice hsp70 gene expressed at normal temperature and the expression was enhanced by heat shock treatment.     

The structure and expression of maize genes encoding the major heat shock protein, hsp70

We have isolated and sequenced two maize genomic clones that are homologous to the Drosophila hsp70 gene. One of the maize hsp70 clones contains the entire hsp70 coding region and 81 nucleotides of the 5' nontranslated sequence. The predicted amino acid sequence for this maize protein is 68% homologous to the hsp70 of Drosophila. The second maize hsp70 clone contains only part of the coding sequence and 1.1 kb of the 5' flanking sequence. This 5' flanking sequence contains two sequences homologous to the consensus heat-shock-element sequence. Both maize genes are thermally inducible and each contains an intron in the same position as that of the heat-shock-cognate gene, hsc1, of Drosophila. The presence of an intron in the maize genes is a distinguishing feature in that no other thermally inducible hsp70 genes described to date contain an intron. We have constructed a hybrid hsp70 gene containing the entire hsp70 coding sequence with an intron, and 1.1 kb of the 5' flanking sequence. We demonstrate that this hybrid gene is thermally inducible in a transgenic petunia plant and that the gene is expressed from its own promoter.     

Sequence of a sea urchin hsp70 gene and its 5' flanking region

We report the nucleotide sequence of a 4470-bp fragment derived from a sea urchin genomic clone containing part of a heat-shock protein 70 (Hsp70)-encoding gene. This fragment, named hsp70 gene II, contains 1271 bp of the flanking region and 3299 bp of structural gene sequence interrupted by five introns and encoding the N-terminal 371 amino acids (aa) of the protein. The 5' flanking region contains a putative TATA element, two CCAAT boxes, four heat-shock consensus sequence elements (hse) and one consensus sequence for binding of Sp1. Remarkable homologies were observed for deduced aa sequence and intron-exon organization between hsp70 gene II and rat hsc73 gene.     

Molecular characterization of the first heat shock protein 70 from a reef coral.

The branching coral Stylophora pistillata, one of the most abundant hermatypic corals along the coasts of the Red Sea, has been used for many years as a model species for coral biological studies. Here we characterize the first coral heat shock protein 70 gene (SP-HSP70), cloned from S. pistillata, to be used as a tool for studying coral stress response. The cloning was carried out by a combination of PCR methods using heterologous, degenerate HSP70-based primers, followed by plaque-lift screening of a genomic library. The sequenced clone (5212 bp), contains a complete 1953 bp, intronless open reading frame, and 5' and 3' flanking regions of 1,935 and 1,324 bp, respectively. TATA, CAAT, and ATF boxes as well as 11 putative heat shock elements were identified in the SP-HSP70 5' flanking region. A polyadenylation site was identified in the 3' flanking region. SP-HSP70 protein sequence resembles the cytosolic/nuclear HSP70 cluster. RT-PCR studies confirmed SP-HSP70 mRNA expression in corals grown within their normal physiological conditions. Furthermore, SP-HSP70 has been shown to belong to the coral genome and not to its symbiotic algae one, as revealed by SP-HSP70 PCR amplification, using purified algal and coral DNA templates.     

The rat casein multigene family. Fine structure and evolution of the beta-casein gene

Eight overlapping phage clones, spanning 34.4 kilobase pairs of genomic DNA, containing the 7.2-kilobase pair rat beta-casein gene have been isolated and characterized. The first 510 base pairs (bp) of 5' flanking, 110 bp of 3' flanking, and all the exon/intron junctions have been sequenced. The beta-casein gene contains 9 exons ranging in size from 21 to 525 bp. We have attempted to identify potential regulatory elements by searching for regions of sequence homology shared between milk protein genes which respond similarly to lactogenic hormones and by searching for previously reported hormone receptor-binding sites. Within the conserved first 200 bp of 5' flanking sequences 3 regions of greater than 70% homology were observed between the rat beta- and gamma-casein genes. One of these contains a region 90% homologous to the chicken progesterone receptor-binding site. The conserved 5' noncoding region, the highly conserved signal peptide, and the hydrophobic carboxyl-terminal region of the protein are each encoded by a separate exon. In contrast the evolutionarily conserved phosphorylation site of beta-casein is formed by an RNA-splicing event. The exons which encode the phosphorylation sites of beta-casein appear to have resulted from an intragenic duplication. Based upon the exon structure of the casein genes, an evolutionary model of intragenic and intergenic exon duplications for this gene family is proposed.     

Expression of the Tribolium castaneum （Coleoptera： Tenebrionidae） hsp83 gene and its relation to oogenesis during ovarian maturation

Heat shock proteins (HSP) can protect organisms and cells from thermal damage. In this study, we cloned the full length cDNA encoding the HSP83 protein (the homologue of HSP90) of Tribolium castaneum (red flour beetle). The isolated cDNA contains the full coding sequence, a partial 5′ untranslated region of 55 bp and the complete 3′ untranslated region. We found the hsp83 gene is located on chromosome 5 of the T. castaneum genome. The predicted HSP83 protein sequence has a high similarity (on average 86.77%) with that of other insect species. The expression of the hsp83 gene in the whole body and in the ovary could be induced with heat stress (40°C for 1 h) in newly hatched (within 3 h post emergence) and mature (10 days post emergence) beetles. Under normal conditions, the hsp83 expression in the ovary is about 3-fold higher than in the whole body at both stages. No significant difference in hsp83 expression was observed between the two ovarian developmental stages regardless if the beetles were treated with heat shock or not. The expression of the HSP83 protein in the whole body could also be induced with heat stress in newly hatched and mature beetles. However, in the ovary, HSP83 was only expressed in the follicle cells of mature beetles and not in newly hatched beetles, regardless if the beetles were treated with heat shock or not. Furthermore, the females were not able to produce mature oocytes after knock-down of the hsp83 expression by injecting dsRNA. These results suggest that the HSP83 protein is involved in protection against heat stress and could be involved in oogenesis during ovarian maturation of T. castaneum.     

Characterization of the 5' flanking region of the rat Na+/K(+)-ATPase beta 1 subunit gene.

We have isolated the 5' end of the rat Na+/K(+)-ATPase beta 1 subunit gene. A genomic fragment containing 817 bp of the 5' flanking sequence, exon 1 and 479 bp of intron 1 was sequenced. The 5' flanking region contains a potential TATA box and several putative CAAT and GC boxes. Potential binding sites for thyroid and glucocorticoid receptors were identified together with multiple sequence motifs which exhibit homology to calcium and serum responsive elements.     

Two human gamma-crystallin genes are linked and riddled with Alu-repeats

A human genomic cosmid clone, pHcos gamma-1, has been isolated containing two closely linked gamma-crystallin genes, oriented in the same direction. The sequence of these genes and their 5' and 3' flanking regions has been determined. The coding regions of both genes are interrupted by two introns. The first introns (94 and 100 bp, respectively) are located in the 5' region of the genes. The second introns (2.82 and 0.95 kb, respectively) divide the genes into two halves, each encoding a structural domain of the gamma-crystallin protein. The coding regions of the two genes show 80% homology. Due to a mutation in the splice acceptor site of the second intron of the first gene, the coding region of its third exon is 3 bp longer than that of the second gene. In the flanking regions several conserved sequence elements were found, including those elements that are known to be necessary for the correct expression of eukaryotic genes. The flanking and intronic regions of the genes contain 'simple sequence' DNA and Alu repeats. The Alu repeats are usually clustered, contain truncated elements, and are often located near simple sequence DNA.