scholarly journals Sequence and regulation of a gene encoding a human 89-kilodalton heat shock protein.

1989 ◽  
Vol 9 (6) ◽  
pp. 2615-2626 ◽  
Author(s):  
E Hickey ◽  
S E Brandon ◽  
G Smale ◽  
D Lloyd ◽  
L A Weber

Vertebrate cells synthesize two forms of the 82- to 90-kilodalton heat shock protein that are encoded by distinct gene families. In HeLa cells, both proteins (hsp89 alpha and hsp89 beta) are abundant under normal growth conditions and are synthesized at increased rates in response to heat stress. Only the larger form, hsp89 alpha, is induced by the adenovirus E1A gene product (M. C. Simon, K. Kitchener, H. T. Kao, E. Hickey, L. Weber, R. Voellmy, N. Heintz, and J. R. Nevins, Mol. Cell. Biol. 7:2884-2890, 1987). We have isolated a human hsp89 alpha gene that shows complete sequence identity with heat- and E1A-inducible cDNA used as a hybridization probe. The 5'-flanking region contained overlapping and inverted consensus heat shock control elements that can confer heat-inducible expression on a beta-globin reporter gene. The gene contained 10 intervening sequences. The first intron was located adjacent to the translation start codon, an arrangement also found in the Drosophila hsp82 gene. The spliced mRNA sequence contained a single open reading frame encoding an 84,564-dalton polypeptide showing high homology with the hsp82 to hsp90 proteins of other organisms. The deduced hsp89 alpha protein sequence differed from the human hsp89 beta sequence reported elsewhere (N. F. Rebbe, J. Ware, R. M. Bertina, P. Modrich, and D. W. Stafford (Gene 53:235-245, 1987) in at least 99 out of the 732 amino acids. Transcription of the hsp89 alpha gene was induced by serum during normal cell growth, but expression did not appear to be restricted to a particular stage of the cell cycle. hsp89 alpha mRNA was considerably more stable than the mRNA encoding hsp70, which can account for the higher constitutive rate of hsp89 synthesis in unstressed cells.

1989 ◽  
Vol 9 (6) ◽  
pp. 2615-2626
Author(s):  
E Hickey ◽  
S E Brandon ◽  
G Smale ◽  
D Lloyd ◽  
L A Weber

Vertebrate cells synthesize two forms of the 82- to 90-kilodalton heat shock protein that are encoded by distinct gene families. In HeLa cells, both proteins (hsp89 alpha and hsp89 beta) are abundant under normal growth conditions and are synthesized at increased rates in response to heat stress. Only the larger form, hsp89 alpha, is induced by the adenovirus E1A gene product (M. C. Simon, K. Kitchener, H. T. Kao, E. Hickey, L. Weber, R. Voellmy, N. Heintz, and J. R. Nevins, Mol. Cell. Biol. 7:2884-2890, 1987). We have isolated a human hsp89 alpha gene that shows complete sequence identity with heat- and E1A-inducible cDNA used as a hybridization probe. The 5'-flanking region contained overlapping and inverted consensus heat shock control elements that can confer heat-inducible expression on a beta-globin reporter gene. The gene contained 10 intervening sequences. The first intron was located adjacent to the translation start codon, an arrangement also found in the Drosophila hsp82 gene. The spliced mRNA sequence contained a single open reading frame encoding an 84,564-dalton polypeptide showing high homology with the hsp82 to hsp90 proteins of other organisms. The deduced hsp89 alpha protein sequence differed from the human hsp89 beta sequence reported elsewhere (N. F. Rebbe, J. Ware, R. M. Bertina, P. Modrich, and D. W. Stafford (Gene 53:235-245, 1987) in at least 99 out of the 732 amino acids. Transcription of the hsp89 alpha gene was induced by serum during normal cell growth, but expression did not appear to be restricted to a particular stage of the cell cycle. hsp89 alpha mRNA was considerably more stable than the mRNA encoding hsp70, which can account for the higher constitutive rate of hsp89 synthesis in unstressed cells.


1992 ◽  
Vol 70 (12) ◽  
pp. 1347-1355 ◽  
Author(s):  
H. S. Roychowdhury ◽  
T. J. MacAlister ◽  
J. W. Costerton ◽  
M. Kapoor

The most abundant heat-shock protein of Neurospora crassa is a multimeric glycoprotein of 80-kilodaltons (i.e., HSP80), induced strongly by hyperthermia and at a lower level by sodium arsenite, ethanol, and carbon source depletion. Immunoelectron microscopy, using indirect immunogold labelling demonstrated that HSP80 was undetectable in mycelium cultured at the normal growth temperature of 28 °C, but it appeared rapidly following the commencement of heat-shock treatment at 48 °C. HSP80, visualized by the gold label, was observed almost exclusively in the cytoplasm, exhibiting a uniform distribution. Association of this protein with cellular membranes and (or) targeting to a particular subcellular compartment or organelle was not apparent.Key words: 80-kilodalton heat-shock protein, Neurospora, intracellular location, immunoelectron microscopy.


1988 ◽  
Vol 8 (9) ◽  
pp. 3827-3836
Author(s):  
N P Williams ◽  
P P Mueller ◽  
A G Hinnebusch

Translational control of GCN4 expression in the yeast Saccharomyces cerevisiae is mediated by multiple AUG codons present in the leader of GCN4 mRNA, each of which initiates a short open reading frame of only two or three codons. Upstream AUG codons 3 and 4 are required to repress GCN4 expression in normal growth conditions; AUG codons 1 and 2 are needed to overcome this repression in amino acid starvation conditions. We show that the regulatory function of AUG codons 1 and 2 can be qualitatively mimicked by the AUG codons of two heterologous upstream open reading frames (URFs) containing the initiation regions of the yeast genes PGK and TRP1. These AUG codons inhibit GCN4 expression when present singly in the mRNA leader; however, they stimulate GCN4 expression in derepressing conditions when inserted upstream from AUG codons 3 and 4. This finding supports the idea that AUG codons 1 and 2 function in the control mechanism as translation initiation sites and further suggests that suppression of the inhibitory effects of AUG codons 3 and 4 is a general consequence of the translation of URF 1 and 2 sequences upstream. Several observations suggest that AUG codons 3 and 4 are efficient initiation sites; however, these sequences do not act as positive regulatory elements when placed upstream from URF 1. This result suggests that efficient translation is only one of the important properties of the 5' proximal URFs in GCN4 mRNA. We propose that a second property is the ability to permit reinitiation following termination of translation and that URF 1 is optimized for this regulatory function.


1993 ◽  
Vol 13 (2) ◽  
pp. 749-761
Author(s):  
G J Gallo ◽  
H Prentice ◽  
R E Kingston

Schizosaccharomyces pombe is becoming an increasingly useful organism for the study of cellular processes, since in certain respects, such as the cell cycle and splicing, it is similar to metazoans. Previous biochemical studies have shown that the DNA binding ability of S. pombe heat shock factor (HSF) is fully induced only under stressed conditions, in a manner similar to that of Drosophila melanogaster and humans but differing from the constitutive binding by HSF in the budding yeasts. We report the isolation of the cDNA and gene for the HSF from S. pombe. S. pombe HSF has a domain structure that is more closely related to the structure of human and D. melanogaster HSFs than to the structure of the budding yeast HSFs, further arguing that regulation of HSF in S. pombe is likely to reflect regulation in metazoans. Surprisingly, the S. pombe HSF gene is required for growth at normal temperatures. We show that the S. pombe HSF gene can be replaced by the D. melanogaster HSF gene and that strains containing either of these genes behave similarly to transiently heat-shocked strains with respect to viability and the level of heat-induced transcripts from heat shock promoters. Strains containing the D. melanogaster HSF gene, however, have lower growth rates and show altered morphology at normal growth temperatures. These data demonstrate the functional conservation of domains of HSF that are required for response to heat shock. They further suggest a general role for HSF in growth of eukaryotic cells under normal (nonstressed) growth conditions.


Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1074
Author(s):  
Xuan Chen ◽  
Ze-Dong Li ◽  
Yi-Ting Dai ◽  
Ming-Xing Jiang ◽  
Chuan-Xi Zhang

Hsp90 (heat shock protein 90) chaperone machinery is considered to be a key regulator of proteostasis under both physiological and stress growth conditions in eukaryotic cells. The high conservation of both the sequence and function of Hsp90 allows for the utilization of various species to explore new phenotypes and mechanisms. In this study, three Hsp90 homologs were identified in the brown planthopper (BPH), Nilaparvata lugens: cytosolic NlHsp90, endoplasmic reticulum (ER) NlGRP94 and mitochondrial NlTRAP1. Sequence analysis and phylogenetic construction showed that these proteins belonged to distinct classes consistent with the predicted localization and suggested an evolutionary relationship between NlTRAP1 and bacterial HtpG (high-temperature protein G). Temporospatial expression analyses showed that NlHsp90 was inducible under heat stress throughout the developmental stage, while NlGRP94 was only induced at the egg stage. All three genes had a significantly high transcript level in the ovary. The RNA interference-mediated knockdown of NlHsp90 its essential role in nymph development and oogenesis under physiological conditions. NlGRP94 was also required during the early developmental stage and played a crucial role in oogenesis, fecundity and late embryogenesis. Notably, we first found that NlHsp90 and NlGRP94 were likely involved in the cuticle structure of female BPH. Together, our research revealed multifunctional roles of Hsp90s in the BPH.


1995 ◽  
Vol 305 (1) ◽  
pp. 197-203 ◽  
Author(s):  
J A Gutierrez ◽  
V Guerriero

A cDNA clone for the stress-inducible 70 kDa heat-shock protein (Hsp70) has been isolated from a bovine skeletal-muscle cDNA library. This mRNA encodes a protein with a calculated molecular mass of 70250 Da. The cDNA has one continuous open reading frame capable of encoding a 641-amino-acid protein. Expression of this cDNA in a bacterial expression system produced a protein with a mobility identical with that of the inducible Hsp70 protein from bovine skeletal muscle as determined by SDS/PAGE. Two-dimensional gel electrophoresis demonstrated this protein to have focusing properties identical with that of a minor isoform from bovine skeletal muscle. Upon carbamylation of this bacterially expressed protein, a train of charged proteins with charge differences of -1 were produced. These carbamylated proteins were shown to have similar focusing mobilities to the Hsp70 isoforms isolated from bovine skeletal muscle. These results demonstrate the identification of a skeletal-muscle inducible Hsp70 gene and suggest that the presence of multiple Hsp70 isoforms may be the product of post-translational modifications to the Hsp70 proteins.


2014 ◽  
Vol 27 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Jin-Ho Baek ◽  
Jin-Ah Park ◽  
Jung-Mi Kim ◽  
Jung-Mi Oh ◽  
Seung-Moon Park ◽  
...  

A small heat-shock protein gene, CpHsp24, of Cryphonectria parasitica was selected based on its expression pattern, which showed that it was tannic acid inducible and that its induction was severely hampered by a hypovirus. The predicted protein sequence of CpHsp24 consisted of a hallmark α-crystalline domain flanked by a variable N-terminal and a short C-terminal region. Disruption of CpHsp24 resulted in a slow growth rate under standard growth conditions. The CpHsp24-null mutant showed enhanced sensitivity to heat shock, which was consistent with Northern and Western analyses displaying the heat-shock induction of the CpHsp24 gene and protein, respectively. Virulence tests on the excised bark revealed a severe decrease in the necrotic area of the CpHsp24-null mutant. When the hypovirus was transferred, virus-containing CpHsp24-null progeny displayed severely retarded growth patterns with hypovirulent characteristics of reduced pigmentation and sporulation. Because the tannic-acid-inducible and hypoviral-suppressible expression and the severely impaired virulence are also characteristics of the laccase3 gene (lac3), lac3 expression in the CpHsp24-null mutant was also examined. The resulting lac3 induction was severely affected in the CpHsp24-null mutant, suggesting that CpHsp24 is important for lac3 induction and that CpHsp24 may act as a molecular chaperone for the lac3 protein.


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