Nuclear Protein Following Heat Shock: Protein Removal Kinetics and Cell Cycle Rearrangements

1986 ◽  
Vol 107 (2) ◽  
pp. 250 ◽  
Author(s):  
Joseph L. Roti Roti ◽  
Nazan Uygur ◽  
Ryuji Higashikubo
Keyword(s):  
Cell Cycle ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Nuclear Protein

scholarly journals Heat shock protein 27 promotes cell cycle progression by down-regulating E2F transcription factor 4 and retinoblastoma family protein p130

2018 ◽  
Vol 293 (41) ◽  
pp. 15815-15826 ◽  
Author(s):  
Ah-Mee Park ◽  
Ikuo Tsunoda ◽  
Osamu Yoshie
Keyword(s):  
Cell Cycle ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Cellular Senescence ◽  
Cell Cycle Progression ◽  
Heat Shock Protein 27 ◽  
Serum Starvation ◽  
Cell Cycle Gene ◽  
Cycle Progression ◽  
Human Lung Fibroblast

Heat shock protein 27 (HSP27) protects cells under stress. Here, we demonstrate that HSP27 also promotes cell cycle progression of MRC-5 human lung fibroblast cells. Serum starvation for 24 h induced G1 arrest in these cells, and upon serum refeeding, the cells initiated cell cycle progression accompanied by an increase in HSP27 protein levels. HSP27 levels peaked at 12 h, and transcriptional up-regulation of six G2/M-related genes (CCNA2, CCNB1, CCNB2, CDC25C, CDCA3, and CDK1) peaked at 24–48 h. siRNA-mediated HSP27 silencing in proliferating MRC-5 cells induced G2 arrest coinciding with down-regulation of these six genes. Of note, the promoters of all of these genes have the cell cycle–dependent element and/or the cell cycle gene-homology region. These promoter regions are known to be bound by the E2F family proteins (E2F-1 to E2F-8) and retinoblastoma (RB) family proteins (RB1, p107, and p130), among which E2F-4 and p130 were strongly up-regulated in HSP27-knockdown cells. E2F-4 or p130 knockdown concomitant with the HSP27 knockdown rescued MRC-5 cells from G2 arrest and up-regulated the six cell cycle genes. Moreover, we observed cellular senescence in MRC-5 cells on day 3 after the HSP27 knockdown, as evidenced by increased senescence-associated β-gal activity and up-regulated inflammatory cytokines. The cellular senescence was also suppressed by the concomitant knockdown of E2F-4/HSP27 or p130/HSP27. Our findings indicate that HSP27 promotes cell cycle progression of MRC-5 cells by suppressing expression of the transcriptional repressors E2F-4 and p130.

scholarly journals Heat-Shock Protein 90 Controls the Expression of Cell-Cycle Genes by Stabilizing Metazoan-Specific Host-Cell Factor HCFC1

Cell Reports ◽  
2019 ◽  
Vol 29 (6) ◽  
pp. 1645-1659.e9 ◽  
Author(s):  
Aneliya Antonova ◽  
Barbara Hummel ◽  
Ashkan Khavaran ◽  
Desiree M. Redhaber ◽  
Fernando Aprile-Garcia ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Host Cell ◽  
Heat Shock Protein 90 ◽  
Cell Cycle Genes ◽  
Specific Host ◽  
Host Cell Factor

scholarly journals 2-phenylethynesulfonamide inhibits growth of oral squamous cell carcinoma cells by blocking the function of heat shock protein 70

2020 ◽  
Vol 40 (3) ◽  
Author(s):  
Liang Jiang ◽  
Jing Xiao
Keyword(s):  
Cell Cycle ◽  
Squamous Cell Carcinoma ◽  
Heat Shock ◽  
Oral Squamous Cell Carcinoma ◽  
Heat Shock Protein ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Heat Shock Protein 70 ◽  
Phosphorylated Akt ◽  
Apoptosis Protein

Abstract Oral squamous cell carcinoma (OSCC) is the most common malignancy in the oral cavity, which accounts for >90% of all diagnosed oral cancers. 2-phenylethynesulfonamide (PES) was known as a selective heat shock protein 70 (Hsp70) function inhibitor, which induced cytotoxic effects on various tumor cell types, but showed to be less toxic to normal cells. However, no associated evaluation of PES on OSCC was found. In the present study, the proliferation of OSCC cells treated with PES was analyzed using a CCK-8 assay. The effects of PES on the cell cycle and apoptosis of OSCC cells were determined by flow cytometric analyses. Expression of associated protein was determined by Western blot analysis. The results of the present study showed that PES inhibited the proliferation of OSCC cell lines in vivo and in vitro. PES induced apoptosis and arrested the cell cycle of OSCC cells. PES inhibited the expression of X-linked inhibitor of apoptosis protein (XIAP), baculoviral IAP repeat containing 2 (c-IAP1), phosphorylated AKT (p-AKT), and phosphorylated extracellular signal-regulated kinase (p-ERK). Additionally, knockdown of Hsp70 enhanced the effects of PES. By contrast, overexpression of Hsp70 attenuated the inhibitory effects of PES on cell viability. PES disrupted the interaction between Hsp70 and XIAP. In conclusion, the present study demonstrated that PES suppresses the growth of OSCC cells through Hsp70-dependent mechanism.

Heat-shock protein 70 attenuates nitric oxide-induced apoptosis in RAW macrophages by preventing cytochrome c release

2002 ◽  
Vol 362 (3) ◽  
pp. 635-641 ◽  
Author(s):  
Sabine D. KLEIN ◽  
Bernhard BRÜNE
Keyword(s):  
Nitric Oxide ◽  
Cell Cycle ◽  
Heat Shock ◽  
Cytochrome C ◽  
Heat Shock Protein ◽  
Cytochrome C Release ◽  
Interacting Protein ◽  
P53 Expression ◽  
Induced Apoptosis ◽  
Hoechst Staining

Heat-shock protein (Hsp) 70 is an inhibitor of apoptosis and has been shown to protect against nitric oxide-mediated toxicity. To gain mechanistic insights into the actions of Hsp70, we stably transfected RAW 264.7 mouse macrophages with the human Hsp70 gene and investigated critical steps in the progression towards cell demise. Incubation of control and Hsp70-transfected macrophages with S-nitrosoglutathione induced accumulation of the tumour suppressor p53, expression of p21WAF1/CIP1 (where WAF1 corresponds to wild-type p53-activated fragment 1 and CIP1 corresponds to cyclin-dependent kinase-interacting protein 1) and G1 cell-cycle arrest. However, cytochrome c translocation to the cytosol and activation of caspase 9 and caspase 3 were markedly reduced in Hsp70-overexpressing cells. In addition, changes in nuclear morphology, as determined by Hoechst staining, and the appearance of cells in the sub-G1 phase were diminished in Hsp70-overexpressing cells compared with controls. We conclude that, in macrophages, Hsp70 interferes with cytochrome c release from mitochondria and, thereby, prevents nitric oxide-induced apoptosis, but leaves p53 accumulation and interference in the cell cycle intact.

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