scholarly journals Heat shock-induced translational alterations in HeLa cells. Initiation factor modifications and the inhibition of translation.

1984 ◽  
Vol 259 (19) ◽  
pp. 11882-11889
Author(s):  
R Duncan ◽  
J W Hershey
Keyword(s):  
Heat Shock ◽  
Hela Cells ◽  
Initiation Factor

scholarly journals Cleavage of Eukaryotic Translation Initiation Factor 4G by Exogenously Added Hybrid Proteins Containing Poliovirus 2Apro in HeLa Cells: Effects on Gene Expression

1999 ◽  
Vol 19 (4) ◽  
pp. 2445-2454 ◽  
Author(s):  
Isabel Novoa ◽  
Luis Carrasco
Keyword(s):  
Heat Shock ◽  
Hela Cells ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Luciferase Gene ◽  
Normal Medium ◽  
Hypertonic Medium ◽  
Hybrid Proteins ◽  
Eukaryotic Initiation Factor 4G ◽  
In Cells

ABSTRACT Efficient cleavage of both forms of eukaryotic initiation factor 4G (eIF4G-1 and eIF4G-2) has been achieved in HeLa cells by incubation with hybrid proteins containing poliovirus 2Apro. Entry of these proteins into cells is promoted by adenovirus particles. Substantial levels of ongoing translation on preexisting cellular mRNAs still continue for several hours after eIF4G degradation. Treatment of control HeLa cells with hypertonic medium causes an inhibition of translation that is reversed upon restoration of cells to normal medium. Protein synthesis is not restored in cells lacking intact eIF4G after hypertonic treatment. Notably, induction of synthesis of heat shock proteins still occurs in cells pretreated with poliovirus 2Apro, suggesting that transcription and translation of these mRNAs takes place even in the presence of cleaved eIF4G. Finally, the synthesis of luciferase was examined in a HeLa cell line bearing the luciferase gene under control of a tetracycline-regulated promoter. Transcription of the luciferase gene and transport of the mRNA to the cytoplasm occurs at control levels in eIF4G-deficient cells. However, luciferase synthesis is strongly inhibited in these cells. These findings indicate that intact eIF4G is necessary for the translation of mRNAs not engaged in translation with the exception of heat shock mRNAs but is not necessary for the translation of mRNAs that are being translated.

Indomethacin and ibuprofen induce Hsc70 nuclear localization and activation of the heat shock response in HeLa cells

2004 ◽  
Vol 313 (4) ◽  
pp. 863-870 ◽  
Author(s):  
Lucio Lagunas ◽  
C.Matthew Bradbury ◽  
Andrei Laszlo ◽  
Clayton R Hunt ◽  
David Gius
Keyword(s):  
Heat Shock ◽  
Nuclear Localization ◽  
Hela Cells ◽  
Heat Shock Response ◽  
Shock Response

scholarly journals Anticancer Effects of LBA-ST Yogurt Supernatant on HeLa Cells via Heat Shock Protein 27 Decrease In Vitro

2017 ◽  
Vol 6 (1) ◽  
pp. 16
Author(s):  
Liziyyannida Liziyyannida ◽  
Wibi Riawan
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Hela Cells ◽  
Short Chain Fatty Acids ◽  
Heat Shock Protein 27 ◽  
Lactobacillus Bulgaricus ◽  
Culture Cells ◽  
Response To Stress ◽  
And Migration

Heat Shock Protein 27 (Hsp27) is overexpressed in cervical cancer as a response to stress conditions. Hsp27 overexpression increase invasion, migration, and adhesion pathways of cancer cells. The Yogurt supernatant contains Short-Chain Fatty Acids (SCFA) include acetate, lactate, and butyrate which have anticancer activity. This study aimed to investigate supernatant of LBA-ST (Lactobacillusbulgaricus-acidophilus, Streptococcusthermophillus) Yogurt can decrease the expression of Hsp27 in HeLa culture cells. The mechanism on how supernatant yogurt inhibit invasion, migration, and adhesion was studied by immunocytochemistry. The data was then collected and analyzed using One-Way ANOVA. From this study, it can be concluded that the expression of proteins that play a role in invasion, adhesion, and migration of the Hsp27 was proven to be decreased (p< 0.05 ± 0.005).Keywords: HeLa cells, yogurt supernatant, Lactobacillus bulgaricus-acidophilus, Streptococcus thermophillus, Hsp27

A stress-inducible 40 kDa protein (hsp40): purification by modified two-dimensional gel electrophoresis and co-localization with hsc70(p73) in heat-shocked HeLa cells

1993 ◽  
Vol 104 (3) ◽  
pp. 629-638 ◽  
Author(s):  
H. Hattori ◽  
T. Kaneda ◽  
B. Lokeshwar ◽  
A. Laszlo ◽  
K. Ohtsuka
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Hela Cells ◽  
Gel Electrophoresis ◽  
Recovery Period ◽  
Chinese Hamster ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Terminal Amino ◽  
Kinetics Of

We have previously reported that a novel 40 kDa protein is induced by heat shock and several environmental stresses in mammalian and avian cells and that the N-terminal amino acid sequence of this 40 kDa protein has homology with the bacterial DnaJ heat-shock protein. We have purified this protein (40 kDa heat-shock protein, hsp40) from HeLa cells by modified two-dimensional gel electrophoresis and generated a polyclonal antibody against hsp40. This antibody was highly specific for human hsp40 and cross-reacted weakly with rat and Chinese hamster hsp40. Indirect immunofluorescence revealed that the hsp40 in HeLa cells accumulates in the nucleus, especially in the nucleolus, during heat shock and returns to the cytoplasm during the recovery period. The kinetics of the accumulation in the nucleoli and subsequent return to the cytoplasm of hsp40 was similar to that of hsp70. In addition, hsp40 was co-localized with hsc70(p73) in heat-shocked HeLa cells as demonstrated by double immunofluorescence staining. These results suggest that hsp40 (a DnaJ homologue) and hsp70 (a DnaK homologue) may act in concert to repair (refold) denatured proteins and protein aggregates in the nuclei and nucleoli of heat-shocked HeLa cells.

scholarly journals P0015SIRT2 REGULATES CISPLATIN-INDUCED ENDOPLASMIC RETICULUM STRESS THROUGH HEAT SHOCK FACTOR 1 DEACETYLATION

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Woong Park ◽  
Hyeongwan Kim ◽  
Yujin Jung ◽  
Kyung Pyo Kang ◽  
Won Kim
Keyword(s):  
Endoplasmic Reticulum ◽  
Heat Shock ◽  
Er Stress ◽  
Knockout Mice ◽  
Malignant Tumors ◽  
Heat Shock Factor ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Heat Shock Factor 1 ◽  
Caspase 12

Abstract Background and Aims Nephrotoxicity is an important cisplatin-induced adverse reaction and restricts the use of cisplatin to treat malignant tumors. Endoplasmic reticulum (ER) stress is caused by the accumulation of misfolded proteins, and is induced by cisplatin in kidneys. SIRT2 nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase is a member of the sirtuin family, but its role in cisplatin-induced ER stress remains unclear. Method To investigate the effect of SIRT2 on cisplatin-induced ER stress using SIRT2 knockout mice and human proximal tubular epithelial cells (HK-2 cells). We treated cisplatin (20 µg/mL) or induced by intraperitoneal injection of cisplatin (20 mg/kg) and evaluated the changes of ER stress and its signal mechanism. Results Cisplatin administration was found to significantly increase the expressions of PRKR-like ER kinase (PERK), phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), and the C/EBP homologous protein (CHOP) and caspase-12 in the kidneys of SIRT2-wild type mice. However, cisplatin-induced increases in the expressions of p-PERK, p-eIF2α, CHOP and, caspase-12 were diminished in kidneys of SIRT2 knockout mice. In vitro, cisplatin significantly increased the expressions of p-PERK, p-eIF2α, CHOP, and caspase-12 in HK-2 cells. When the effect of SIRT2 on cisplatin-induced ER stress was evaluated using SIRT2-siRNA (ON-TARGET plus human SIRT2 siRNA) or the SIRT2 inhibitors, AGK2 and AK1, knockdown or inhibition of SIRT2 significantly attenuated the cisplatin-induced protein expression of p-PERK, p-eIF2α, CHOP, and caspase-12. Immunoprecipitation studies showed SIRT2 bound physically to heat shock factor (HSF)1 and that HSF1 acetylation was significantly increased by cisplatin. In addition, knockdown of SIRT2 increased cisplatin-induced HSF1 acetylation and increased the expression of heat shock protein (HSP)70. Conclusion These observations suggest that suppression of SIRT2 ameliorates cisplatin-induced ER stress by increasing HSF1 acetylation and HSP expression.

Head-down tilt increases rat cardiac muscle eIF-2 alpha phosphorylation

1995 ◽  
Vol 269 (3) ◽  
pp. C802-C804 ◽  
Author(s):  
V. Menon ◽  
D. B. Thomason
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein 70 ◽  
Center Of Mass ◽  
Electrophoretic Analysis ◽  
Initiation Factor ◽  
Two Dimensional ◽  
Eukaryotic Initiation Factor ◽  
Hsp 70 ◽  
Initiation Rate ◽  
Initiation Factor 2

We previously demonstrated that head-down tilt in rats decreases heart polypeptide initiation rate and proposed a mechanism whereby redistribution of the chaperone heat-shock cognate/heat-shock protein-70 (HSC/HSP-70) facilitates the phosphorylation of eukaryotic initiation factor-2 alpha (eIF-2 alpha). In this study, two-dimensional gel electrophoretic analysis of eIF-2 alpha showed no phosphorylation in control hearts. At 8 h of head-down tilt, there was a 45% increase in total eIF-2 alpha, and 79% was phosphorylated. At 18 h, eIF-2 alpha increased to 142% of control, of which 4% was phosphorylated. This is consistent with the previous study where, at 8 h, there was a 78% increase in polysomal HSC/HSP-70 and a shift in the polysome center-of-mass to lighter polysomes (indicating decreased initiation). After 18 h of suspension, polysomal HSC/HSP-70 levels were 24% relative to control, and the center-of-mass returned toward control. We conclude that the decrease in polypeptide initiation during head-down tilt is mediated by HSC/HSP-70 via phosphorylation of eIF-2 alpha.

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