共查询到20条相似文献,搜索用时 46 毫秒
1.
Doerwald L van Genesen ST Onnekink C Marín-Vinader L de Lange F de Jong WW Lubsen NH 《Cellular and molecular life sciences : CMLS》2006,63(6):735-743
The mechanism of the translational thermotolerance provided by the small heat shock proteins (sHsps) αB-crystallin or Hsp27
is unknown. We show here that Hsp27, but not αB-crystallin, increased the pool of mobile stress granule-associated enhanced
green fluorescent protein (EGFP)-eukaryotic translation initiation factor (eIF)4E in heat-shocked cells, as determined by
fluorescence recovery after photobleaching. Hsp27 also partially prevented the sharp decrease in the pool of mobile cytoplasmic
EGFP-eIF4G. sHsps did not prevent the phosphorylation of eIF2α by a heat shock, but promoted dephosphorylation during recovery.
Expression of the C-terminal fragment of GADD34, which causes constitutive dephosphorylation of eIF2α, fully compensated for
the stimulatory effect of αB-crystallin on protein synthesis in heat-shocked cells, but only partially for that of Hsp27.
Our data show that sHsps do not prevent the inhibition of protein synthesis upon heat shock, but restore translation more
rapidly by promoting the dephosphorylation of eIF2α and, in the case of Hsp27, the availability of eIF4E and eIF4G.
Received 9 December 2005; received after revision 16 January 2006; accepted 23 January 2006 相似文献
2.
Exposing cells to adverse conditions usually elicits expression of stress-response (heat shock) proteins (srp). Here we show that hyperosmolar growth conditions do not uniformly affect srp expression in MCF-7 and HeLa S3 cells, derived from carcinoma of the breast and cervix, respectively. Thus, whereas srp 27 expression was increased in MCF-7, but not in HeLa S3, the opposite was the case with srp 72. On the other hand, hyperosmolality did not induce B-crystallin or ubiquitin in either cell line. These findings show that srp expression by the human tumor cells studied is non-coordinate, suggesting that each srp is independently modulated. 相似文献
3.
Jadwiga Jabłońska Magda Dubińska-Magiera Teresa Jagla Krzysztof Jagla Małgorzata Daczewska 《Cellular and molecular life sciences : CMLS》2018,75(23):4341-4356
The Drosophila Hsp67Bc gene encodes a protein belonging to the small heat-shock protein (sHSP) family, identified as the nearest functional ortholog of human HSPB8. The most prominent activity of sHSPs is preventing the irreversible aggregation of various non-native polypeptides. Moreover, they are involved in processes such as development, aging, maintenance of the cytoskeletal architecture and autophagy. In larval muscles Hsp67Bc localizes to the Z- and A-bands, which suggests its role as part of the conserved chaperone complex required for Z-disk maintenance. In addition, Hsp67Bc is present at neuromuscular junctions (NMJs), which implies its involvement in the maintenance of NMJ structure. Here, we report the effects of muscle-target overexpression of Drosophila Hsp67Bc hot-spot variants Hsp67BcR126E and Hsp67BcR126N mimicking pathogenic variants of human HSPB8. Depending on the substitutions, we observed a different impact on muscle structure and performance. Expression of Hsp67BcR126E affects larval motility, which may be caused by impairment of mitochondrial respiratory function and/or by NMJ abnormalities manifested by a decrease in the number of synaptic boutons. In contrast, Hsp67BcR126N appears to be an aggregate-prone variant, as reflected in excessive accumulation of mutant proteins and the formation of large aggregates with a lesser impact on muscle structure and performance compared to the Hsp67BcR126E variant. 相似文献
4.
M Ogielska 《Experientia》1990,46(1):98-101
Numerous intramitochondrial paracrystalline inclusion bodies (ICIB) were observed in the germinal plasm of a mid-blastula, and in primordial germ cells (PGCs) after their migration to the germinal ridges, in Rana ridibunda, R. lessonae and R. esculenta. In oogonia the number of ICIB decreases rapidly. Single ICIB are observed in the germ cells up to the leptotene stage; they have never been observed in pachytene oocytes. In diplotene oocytes that have reached a diameter of about 100 microns ICIB are visible again, and their number increases concomitantly with oocyte growth. 相似文献
5.
Goh YC Yap CT Huang BH Cronshaw AD Leung BP Lai PB Hart SP Dransfield I Ross JA 《Cellular and molecular life sciences : CMLS》2011,68(9):1581-1592
Heat-shock protein 60 (Hsp60) is a highly conserved stress protein which has chaperone functions in prokaryotes and mammalian
cells. Hsp60 is associated with the mitochondria and the plasma membrane through phosphorylation by protein kinase A, and
is incorporated into lipid membranes as a protein-folding chaperone. Its diverse intracellular chaperone functions include
the secretion of proteins where it maintains the conformation of precursors and facilitates their translocation through the
plasma membrane. We report here that Hsp60 is concentrated in apoptotic membrane blebs and translocates to the surface of
cells undergoing apoptosis. Hsp60 is also enriched in platelets derived from terminally differentiated megakaryocytes and
expressed at the surface of senescent platelets. Furthermore, the exposure of monocytic U937 cells to Hsp60 enhanced their
phagocytic activity. Our results suggests that externalized Hsp60 in apoptotic cells and senescent platelets influences events
subsequent to apoptosis, such as the clearance of apoptotic cells by phagocytes. 相似文献
6.
The small heat shock protein Hsp27 or its murine homologue Hsp25 acts as an ATP-independent chaperone in protein folding,
but is also implicated in architecture of the cytoskeleton, cell migration, metabolism, cell survival, growth/differentiation,
mRNA stabilization, and tumor progression. A variety of stimuli induce phosphorylation of serine residues 15, 78, and 82 in
Hsp27 and serines 15 and 86 in Hsp25. This post-translational modification affects some of the cellular functions of Hsp25/27.
As a consequence of the functional importance of Hsp25/27 phosphorylation, aberrant Hsp27 phosphorylation has been linked
to several clinical conditions. This review focuses on the different Hsp25/27 kinases and phosphatases that regulate the phosphorylation
pattern of Hsp25/27, and discusses the recent findings of the biological implications of these phosphorylation events in physiological
and pathological processes. Novel therapeutic strategies aimed at restoring anomalous Hsp27 phosphorylation in human diseases
will be presented. 相似文献
7.
M. Ogielska 《Cellular and molecular life sciences : CMLS》1990,46(1):98-101
Summary Numerous intramitochondrial pararystalline inclusion bodies (ICIB) were observed in the germinal plasm of a mid-blastula, and in primordial germ cells (PGCs) after their migration to the germinal ridges, inRana ridibunda, R. lessonae andR. esculenta. In oogonia the number of ICIB decreases rapidly. Single ICIB are observed in the germ cells up to the leptotene stage; they have never been observed in pachytene oocytes. In diplotene oocytes that have reached a diameter of about 100 m ICIB are visible again, and their number increases concomitantly with oocyte growth. 相似文献
8.
Ma Y Cai S Lu Q Lu X Jiang Q Zhou J Zhang C 《Cellular and molecular life sciences : CMLS》2008,65(19):3100-3109
Inhibition of protein deacetylation arrests cells in mitosis, but the mechanism is unknown. To understand why inhibiting protein
deacetylation causes cell cycle arrest, we treated HeLa cells beyond G1/S transition with trichostatin A (TSA), a potent protein
deacetylase inhibitor, and found that the cells arrested at prometaphase with ectopic spindles and unaligned chromosomes.
The hyper-acetylated cells encountered a serious microtubule (MT)-kinetochore attachment problem, although the kinetochores
are intact at ultrastructural level. By immunofluorescence staining of kinetochore proteins, we found that the pericentromeric
H3K9Me3-HP1 pathway was disrupted and that the CENP-A-dependent outer plate protein dynamics of kinetochores was greatly diminished
by the drug treatment. The treatment also caused the loss of chromosome passenger complex (CPC), the proposed error checking
system, from centromere and impaired the microtubule dynamics of the cells. Overall, we propose that deacetylation inhibition
impairs MT-kinetochore attachment through disrupting the centromere function and altering the kinetochore composition and
MT dynamics.
Received 30 April 2008; received after revision 28 July 2008; accepted 14 August 2008 相似文献
9.
Y. Aron M. Vayssier-Taussat M. Bachelet B.S. Polla 《Cellular and molecular life sciences : CMLS》2001,58(10):1522-1527
The anti-ulcer drug geranylgeranylacetone (GGA) has been shown to induce the expression of heat shock proteins (HSPs), in particular of Hsp70, in gastric and small intestine cells. In this study, we investigated whether GGA was able to induce Hsp70 in another cell type, human monocytes, which represent a well-established model of Hsp70 expression under oxidative stress. In these cells, GGA had no significant effect either on basal or tobacco smoke-induced Hsp70 expression. We further investigated the effects of GGA on mitochondria, a key organelle of oxidant-mediated cell injury and a putative target for GGA-mediated protection. GGA significantly increased basal mitochondrial membrane polarization and inhibited the decrease in mitochondrial membrane potential of human monocytes exposed to distinct sources of clinically relevant oxidants such as tobacco smoke and y-irradiation. Our results indicate that mitochondria are targets for GGA-mediated protection against oxidative stress in human monocytes, independently of Hsp70. 相似文献
10.
Heat shock protein 60: regulatory role on innate immune cells 总被引:1,自引:0,他引:1
Human heat shock protein 60 (Hsp60) exhibits immunoregulatory properties, primarily by inducing pro-inflammatory responses
in innate immune cells. Extensive analyses identified specific receptor structures for the interaction of Hsp60 with these
cells. The existence of distinct receptor structures responsible for Hsp60 binding and for Hsp60-induced release of pro-inflammatory
mediators has been demonstrated, implying that the interaction of Hsp60 with innate immune cells is a multifaceted process.
Distinct Hsp60 epitopes responsible for binding to innate immune cells and for the activation of these cells have been identified.
Depending on the cell-type, the amino acid (aa) region 481–500 or the regions aa241–260, aa391–410 and aa461–480 are involved
in Hsp60-binding to innate immune cells. An entirely different Hsp60-region, aa354–365 was found to bind lipopolysaccharide,
thereby mediating the pro-inflammatory effects of Hsp60. Because of its immunoregulatory properties, Hsp60 has been proposed
to act as intercellular danger signal, controlling innate and adaptive immune reactions.
Received 19 September 2006; received after revision 13 October 2006; accepted 13 December 2006 相似文献
11.
Evidence for the possible function of the fluorescent granular perithelial cells in brain as scavengers of high-molecular-weight waste products 总被引:1,自引:0,他引:1
M. Mato S. Ookawara M. Sugamata E. Aikawa 《Cellular and molecular life sciences : CMLS》1984,40(4):399-402
Summary The fluorescent granular perithelium (FGP) of rats and humans under experimental and pathological conditions was examined with the electron microscope. The FGP incorporated high molecular-weight protein (ferritin) and carbon particles administered intraventricularly. In a case of spontaneous cerebral hemorrhage, the FGP was found to contain lipoidal products and minute fragmented cell debris. The FGP in a patient with lipidosis contained pale inclusion bodies. In aged individuals, the inclusion bodies formed irregular larger aggregates. 相似文献
12.
Differential basal synthesis of Hsp70/Hsc70 contributes to interindividual variation in Hsp70/Hsc70 inducibility 总被引:7,自引:0,他引:7
Boshoff T Lombard F Eiselen R Bornman JJ Bachelet M Polla BS Bornman L 《Cellular and molecular life sciences : CMLS》2000,57(8-9):1317-1325
The source of intraspecies variation in the expression of heat shock proteins (HSPs) remains unresolved but could shed light
on differential stress tolerance and disease susceptibility. This study investigated the influence of variable basal HSP synthesis
on differential inducibility of HSP synthesis. Basal and heat-induced synthesis of the major HSP families in peripheral blood
monocytes from healthy donors (n=42) were analysed using biometabolic labelling and densitometry. Basal Hsp70/Hsc70 synthesis
and percentage induction of Hsp70/Hsc70 synthesis were significantly correlated (r=−0.57, p<0.0001), and described most accurately
by an exponential decay equation (R=0.68, R2=0.46). This regression equation suggests that increasing levels of basal Hsp70/Hsc70 synthesis are accompanied byan exponential
decrease in the percentage induction of Hsp70/Hsc70 synthesis. The model fits data from European and non-European population
groups independently, although both coefficients in the regression equation were larger for non-Europeans. This implies population
group as an additional factor influencing differential HSP expression. The differential inducibility of Hsp70/Hsc70 due to
variable basal synthesis of Hsp70/Hsc70 and based upon population group may contribute to differential stress tolerance or
disease susceptibility.
Received 27 March 2000; received after revision 19 June 2000; accepted 20 June 2000 相似文献
13.
14.
X Ronot D Kuch C Hecquet M Adolphe P Lechat G Deysson 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1980,291(12):961-964
The inhibiting effect of Cytembena on HeLa cell kinetics has been demonstrated and analyzed. The percentage of cycling cells decreases, according to the concentration, between 7.5 and 2.5 x 10(-5) M. Estimation of DNA by cell flow cytophotometry shows an important shift in the distribution of cycling cells with a relative decrease of G1 cells and a very important accumulation of G2 cells. According to our experimental conditions, the blocking up in G2 is irreversible only at 7.5 x 10(-5) M. 相似文献
15.
Chiara Giommarelli Valentina Zuco Enrica Favini Claudio Pisano Fabrizio Dal Piaz Nunziatina De Tommasi Franco Zunino 《Cellular and molecular life sciences : CMLS》2010,67(6):995-1004
Curcumin, a natural polyphenol, has been described to exhibit effects on signaling pathways, leading to induction of apoptosis.
In this study, we observed that curcumin inhibited Hsp90 activity causing depletion of client proteins implicated in survival
pathways. Based on this observation, this study was designed to investigate the cellular effects of curcumin combination with
the pan-HDAC inhibitors, vorinostat and panobinostat, which induce hyperacetylation of Hsp90, resulting in inhibition of its
chaperone function. The results showed that, at subtoxic concentrations, curcumin markedly sensitized tumor cells to vorinostat-
and panobinostat-induced growth inhibition and apoptosis. The sensitization was associated with persistent depletion of Hsp90
client proteins (EGFR, Raf-1, Akt, and survivin). In conclusion, our findings document a novel mechanism of action of curcumin
and support the therapeutic potential of curcumin/HDAC inhibitors combination, because the synergistic interaction was observed
at pharmacologically achievable concentrations, which were ineffective when each drug was used alone. 相似文献
16.
17.
G. Tesoriere L. Tesoriere R. Vento M. Giuliano G. Cantoro 《Cellular and molecular life sciences : CMLS》1984,40(7):705-707
Summary D-Glucosamine markedly inhibits thymidine incorporation into the TCA-insoluble fraction and thymidine kinase activity in HeLa cells. Both the inhibitory effects are also observed in isolated retinas of chick embryos. In this case the inhibitory effects are age-dependent and the magnitude of the responses decreases with embryonic development. In addition the time of exposure to D-glucosamine which is necessary to reveal the inhibitory effect on thymidine kinase increases with the age of the embryos. 相似文献
18.
D-Glucosamine markedly inhibits thymidine incorporation into the TCA-insoluble fraction and thymidine kinase activity in HeLa cells. Both the inhibitory effects are also observed in isolated retinas of chick embryos. In this case the inhibitory effects are age-dependent and the magnitude of the responses decreases with embryonic development. In addition the time of exposure to D-glucosamine which is necessary to reveal the inhibitory effect on thymidine kinase increases with the age of the embryos. 相似文献
19.
F. Cian B. Bisiacchi G. D. Rottini P. Patriarca 《Cellular and molecular life sciences : CMLS》1977,33(8):1031-1032
Summary The susceptibility of several strains of E. coli to phagocytic killing by polymorphonuclear leucocytes and the ability of the same strains to invade HeLa cells were studied. It was found that only the strains resistant to killing by leucocytes were able to penetrate and multiply within HeLa cells.Acknowledgments. We thank Dr Bianca Pani who supplied us with HeLa cells. Supported by grant No. 75.00695.04 from the National Research Council of Italy (CNR). 相似文献
20.
The susceptibility of several strains of E. coli to phagocytic killing by polymorphonuclear lencocytes and the ability of the same strains to invade HeLa cells were studied. It was found that only the strains resistant to killing by leucocytes were able to penetrate and multiply within HeLa cells. 相似文献