Gene model reviewed during 5.47
There is only one protein coding transcript and one polypeptide associated with this gene
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Hsp68 using the Feature Mapper tool.
GBrowse - Visual display of RNA-Seq signalsView Dmel\Hsp68 in GBrowse 2
Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Source for identity of: Hsp68 CG5436
Area matching Drosophila HSP68 gene (inverted), Acc. No. J01102.
Synthesis of heat shock proteins is inhibited by both short-chain fatty acids and their corresponding alcohols, compounds which have no observable effect on histone acetylation.
Members of the hsc70 gene family (heat shock cognate genes) that reside within the same intracellular compartment in different organisms share greater amino acid identity than hsc70 proteins from the same organism but different organelles. This pattern of conservation indicates specialisation of hsc70 function.
Nascent chain nuclear run-on assays in KC161 cells reveal different responses to heat shock for different genes. Transcription of His1 is severely inhibited under mild heat shocks, of Act5C decreases proportionally with increasing temperature while that of the core histone genes or the heat shock cognates is repressed only under extreme heat shock. In unshocked cells Hsp83 is moderately transcribed while transcription from the other heat shock genes is undetectable. Engaged but paused RNA molecules are found at the various Hsp70 and Hsp26 genes but not at the other heat shock genes. Increased transcription of the heat shock genes is observed within 1-2 mins of heat shock and maximal rates were reached within 2-5 minutes. Rates of transcription vary over a 20-fold range. Hsrω is transcribed at a very high rate under non-heat shock conditions, and its response to elevated temperatures is different from that of the protein coding heat shock genes.
Probes from D.melanogaster used in chromosome in situ hybridisation to study response to heat shock in D.guanche, D.madeirensis and D.subobscura. Results suggest that the 18C, 94A, 89A and 27A loci of the three obscura group species are homologous to the D.melanogaster loci Hsp83, Hsp70A, Hsp68 and the small Hsp group Hsp22, Hsp23, Hsp26 and Hsp27 respectively.
Exposure of cells to pulses of elevated temperature initiates the heat-shock response. A restricted subset of genes, the Hsp genes, is activated and the majority of transcription and translation is shut down. However, mitochondrial- and histone-gene activities persist (Spradling et al., 1977). This response follows a pulse of 36oC to 40oC; treatments above 40oC inhibit all activity and lead to death; treatments of 30oC-35oC induce heat-shock-protein synthesis without repressing normal protein synthesis (Tissieres, Mitchell and Tracy, 1974). Similar response inducible by other stressful treatments. The response may be elicited at all stages of the life cycle and in cultured cells. Stage specific phenocopies result from heat shocking early stages of Drosophila development (Mitchell and Petersen, 1982). In polytene cells existing puffs regress and a novel group quickly appears at 33B, 63C, 64F, 67B, 70A, 87A, 87C, 93D, 95D (Ashburner, 1970; Tissieres, Mitchell and Tracy, 1974). Activation of transcription of Hsp genes apparently involves the sequential binding of two or more protein factors in vicinity of TATA box (Wu, 1984). Binding sites for these proteins are multiple short upstream sequence elements called HSEs or heat shock consensus elements (Pelham, 1982; Xiao and Lis, 1988). Polymerase II dissociates from most chromosome regions and accumulates at the new puff sites (Bonner and Kerby, 1982). 3H-uridine incorporation ceases at its usual positions and commences at new puff sites. Preexisting polysomes disaggregate and within a few minutes a new population of polysomes appears containing newly transcribed mRNA; this RNA hybridizes to some of the heat-shock puffs. The effects of heat shock may be abrogated to some degree by pretreatment with a pulse of a slightly lower temperature (Mitchell, Moller, Petersen and Lipps-Sarmiento, 1979; Peterson and Mitchell, 1981). For reviews of the heat-shock response see Ashburner and Bonner (1978).
The structural gene for the 68,000 dalton heat-shock protein (HSP68)