Form Of HSF1 Research Articles

Novel SNP identified in HSBP1 gene and its association with thermal tolerance traits in Murrah buffalo

Heat shock response (HSR) is a universal mechanism in all organisms upon heat shock (HS) to prevent stress damages. It is under tight regulation by heat shock factors (HSFs) and heat shock proteins (HSPs). On the attenuation of HSR, Heat Shock Factor Binding Protein1 (HSBP1) interacts with HSF1 and thus converting the active trimer form of HSF1 to inert monomer state. Thus, play an important role in regulating heat shock genes. The present study aimed to explore single nucleotide polymorphism (SNP) in HSBP1 and their association with the thermo tolerance traits (respiration rate, rectal temperature and heat tolerance coefficient) for identification of most thermal adapted Murrah buffaloes. Two hundred female Murrah buffaloes were genotyped using custom sequencing to identify SNP. Only one novel SNPs in exon 3 at position g.1892C>T and two nucleotide variation g.1327C>G and g.1202C>T were identified through direct DNA sequence scanning. Homozygous wild type genotypes (CC) were found in higher frequency (0.84, n=168) than homozygous recessive (0.10, n=20) and heterozygous (0.06, n=12) mutant genotypes at SNP locus g.1892C>T. The association among the different genotype of this SNP locus with thermo tolerance was analyzed using Generalized Linear Model procedure in Statistical Analysis System. However, no significant difference was detected among the genotypes in terms of thermo tolerance traits in the study.

Living in constant crisis--when stress management becomes the problem.

Living in constant crisis--when stress management becomes the problem.

Cytoskeleton protects from stress and aging

Aging The transcription factor HSF-1 has an unexpected second function that allows it to extend longevity in worms. Baird et al. expressed a modified form of HSF-1 in nematodes. The modified protein could not activate genes encoding protein chaperones. Such chaperones are thought to protect many cellular proteins from heat shock and other damage during aging However, the modified protein still extended the worm life span by regulating the transcription of other genes. One gene it regulated was pat-10 , which encodes a troponin-like calcium binding protein. Overexpression of PAT-10 also extended worm life span, apparently by changing the stability of the actin cytoskeleton. Science , this issue p. [360][1] [1]: /lookup/doi/10.1126/science.1253168

Hsf1-Mediated Stress Response can Transiently Enhance Cellular Radioresistance

To elucidate how the heat-shock transcription factor 1 (Hsf1)-mediated stress response affects cellular radioresistance, mouse embryo fibroblasts with Hsf1-gene knockout (Hsf1(-/-) cells) or with normal wild-type Hsf1 expression (Hsf1 wild-type cells) were preconditioned by heating (43 degrees C, 30 min) without or with quercetin (an inhibitor of Hsf1) and then exposed to gamma radiation (4 or 6 Gy). Some cell samples were infected with virus-based vectors to overexpress the constitutively active (mutant) form of Hsf1 or individual heat-shock proteins (Hsps). The heat preconditioning transiently up-regulated the Hsp levels in Hsf1 wild-type cells and significantly improved their postirradiation survival; these effects could be abolished by quercetin or simulated (without preheating) by the Hsf1 overexpression. In contrast, no enhanced radioresistance was found in heat-preconditioned Hsf1(-/-) cells that were unable to trigger Hsf1-mediated Hsp induction after heating. However, when the constitutively active Hsf1 was overexpressed in Hsf1(-/-) cells, the latter accumulated stress-inducible Hsps and became more radioresistant like heat-preconditioned Hsf1 wild-type cells. The overexpression of Hsp70 or/ and Hsp27 also enhanced radioresistance of both cell cultures. Thus the preirradiation stress response resulting in the intracellular Hsp accumulation can improve survival of severely irradiated mammalian cells.

Sensing stress and responding to stress.

Heat shock protein gene expression is enhanced by proteotoxic stress, i.e., by conditions favoring protein unfolding. This upregulation of heat shock protein genes is mediated by heat shock transcription factor HSF1. A mechanism, the details of which are still elusive, senses adverse conditions and causes HSF1 to oligomerize and to acquire DNA-binding ability. The DNA-binding form of HSF1 then undergoes further conformational changes that render it transcriptionally competent. The current model in which heat shock protein 70 acts both as sensor of stress and as negative regulator of HSF1 oligomerization as well as alternative models involving additional protein factors are discussed.