The Pattern of Protein Synthesis Induced by Heat Shock of HeLa Cells (original) (raw)
Related papers
Changes in nuclear proteins induced by heat shock in Drosophila culture cells
FEBS Letters, 1985
Nuclear proteins of normal and heat-shocked Drosophila cells were analysed by two-dimensional electrophoresis. The computerized processing of the gels allowed us to detect 6 proteins strongly induced by the heat treatment, but which were different from the usually described heat-shock proteins. The possible role of these proteins in genetic regulation is discussed, as is the value of this type of approach for the study of other genetic regulation phenomena.
The common fruit fly, Drosophila melanogaster Meigen, is considered to be a model organism and has been employed in numerous studies ranging from the molecular level to the physiological processes of various biological phenomena by the use of its polytene chromosomes and imaginal discs. It has been found that heat stress causes the deterioration of existing puffs and the induction of 9 new puffs observed in the polytene arms with bands 33B, 64C, 64F, 67B, 70A, 87A, 87C, 93D, and 95D. In this study, the untreated and 37°C heat-shocked larvae polytene were similar in gross morphology to the existing cytological map, while the 42°C heat-shocked larvae polytene was not distinguishable.
Biochemical and Immunocytochemical Localization of Heat-Shock Proteins in Drosophila Cultured Cells
Annals of the New York Academy of Sciences, 1985
Treatment of living cells at supraoptimal temperatures or with various chemical or physical aggressors induces the synthesis of a group of proteins known as heat-shock proteins (HSP).'.2 The function of these ubiquitous proteins is unclear although a role in cellular protection has been ~uggested.~ In Drosophila cultured cells, biochemical fractionation of HS cells shows an enrichment of most HSPs (with the exception of HSP 82) in the nuclear pellet following HS.4,' In the course of studies on the characterization of a major intermediate filament-like cytoskeletal protein of 46,000 in these we observed that the group of low molecular weight HSPs tended to copurify with a Triton-high salt insoluble' cytoskeletal fraction (FIGURE 1). In order to investigate the significance of this finding and to elucidate the function of HSPs, we prepared polyclonal antibodies against HSP 82, 70, 68, and 23 and studied their intracellular distribution by immunofluorescence techniques following heat shock and during recovery. The antibodies were purified by affinity and their specificity checked by immunoblotting. The results are summarized in FIGURE 2.
Hyperthermia and the heat-shock proteins of HeLa cells
British journal of cancer, 1982
When HeLa cells are subject to hyperthermia, the synthesis of specific heat-shock proteins (HSP) is induced under a variety of thermal conditions. HSP synthesis does not occur at temperatures above 43 degrees C but requires return to a culture temperature of 37 degrees C. Maximal induction appears to be achieved if a brief hyperthermia treatment (10 min, 45 degrees -46 degrees C) is followed by 2 h "development" at 37 degrees C. The induction process requires transcription but not DNA replication, and general cell metabolism is probably also required, as induction does not occur if the heat-treated cells are returned to 4 degrees (rather than 37 degrees C) for development. A small proportion of the HSPs of 72-74 Kd are found in nuclei, but do not appear to bind to DNA. The bulk of these proteins, as well as those at 100 Kd, are cytoplasmic, but none are preferentially associated with mitochondria. Increased synthesis of the 100Kd and 72-74 Kd HSPs was also triggered by pre...
Journal of Thermal Biology, 2009
The thermotolerance of a species or of an ecotype is important for determining its habitat range and vigour, and considerable research has focused on identifying underlying physiological, biochemical and genetic bases of thermotolerance traits. Rates of protein synthesis in tissues when organisms experience a sudden heat stress as occurs on rare hot days may be important to avoid heat-induced paralysis and to survive. While natural variation in Drosophila melanogaster thermotolerance has been associated with heat-shock gene expression, little attention has been given to examining the thermo-protective role of protein synthesis generally. Using two independently derived sets of single-pair mating lines, we characterised variation in rates of protein synthesis in dissected ovarian tissues, both before and after a heat shock applied at different severities in the two sets. In both sets of lines heat-shocked protein synthesis rates were negatively associated with the increase in heat knockdown tolerance after hardening. These associations occurred in a different sex in each set. Variation in rates of Hsp70 synthesis failed to associate with levels of heat tolerance or general protein synthesis. Our results suggest heritable variation in the rate of protein synthesis following heat stress, independently of Hsp70 variation, contributes to heat tolerance variation in this species.
Localized heat-shock induction in Drosophila melanogaster
The Journal of experimental zoology, 1988
We describe a technique for inducing localized expression of genes fused to heat-shock gene promoters. We demonstrate that a localized heat-shock response can be induced in Drosophila melanogaster at any developmental stage after formation of the cellular blastoderm by contacting a region of the animal with a heated needle. The size of the induced region can be altered by varying parameters such as the temperature and size of the needle tip. The test system utilized here is a D. melanogaster strain transformed with a fusion of the Drosophila hsp26 gene and the E. coli lacZ gene; the activity of this hybrid gene is monitored in whole animals by staining for beta-galactosidase activity. Induced beta-galactosidase activity is confined to the cells in the region of heating; the beta-galactosidase activity can still be detected 48 hr after the heat shock. Given the heat inducibility of Drosophila heat-shock promoters in heterologous systems, we suggest that this technique will be useful ...
Heat shock induced alterations in polyadenylate metabolism in Drosophila melanogaster
Biochemistry, 1980
We have studied the effect of heat shock on poly(adeny1ic acid) [poly(A)] metabolism in Drosophila melanogaster cells by using hybridization of ribonucleic acid (RNA) samples to [3H]poly(uridylic acid). Shortly after heat shock begins, cytoplasmic poly(A) decays rapidly. Two components were detected. Component I constitutes 46% of the total cytoplasmic poly(A) and decays with a half-life of 10 min. Component I1 (54% of total) is more stable. A half-life was not estimated for component I1 because new synthesis was not blocked. Studies on the size of cytoplasmic poly(A) indicate component I is completely degraded while component I1 remains essentially unchanged. Nuclear poly(A) increases rapidly, peaking at 2 or 3 times the normal level after 90 min w h e n cultured cells, larvae, and adult flies of Drosphila melanogaster are transferred from their normal growth temperature of 25 OC to 37 OC a series of regulatory changes rapidly take place [for reviews, see Leenders et al.
Temperature adaptation of Drosophila populations. The heat shock proteins system
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1982
The heat shock proteins (hsps) system has been studied in two replicate cage populations (1D, 1C) of Drosophila melanogaster, which were maintained under different environmental conditions (temperature and relative humidity) for approximately 7 yr and exhibited different survival when they were subjected to temperature shock. 2. The kinetics of protein synthesis in ovaries from D and C flies (and their reciprocal hybrids DC and CD) were subjected to heat stress, and the electrophoretic patterns of heat shock proteins (especially of the hsp 70 K), are correlated with the survival of the fly. 3. These results confirm already obtained results using different stocks which were subjected to different type of selection (indirect selection; Stephanou et al., 1982), which represents good evidence for the biological significance of the hsps. 4. The capacity of protein synthesis (and especially of hsp 70 K) following temperature shock is higher in ovaries from D (25°C) or DC flies as compared with those from C (14°C) or CD ones. 5. It is proposed that the regulation of hsps synthesis can be considered as a major target of temperature-induced selection, and an effective molecular mechanism for temperature compensation.