共查询到20条相似文献,搜索用时 15 毫秒
1.
Di Wu Miao Zhang Yinjun Lu Shu Tang N. Kemper J. Hartung Endong Bao 《Cell stress & chaperones》2016,21(5):817-827
Our recent studies have displayed the protective functions of aspirin against heat stress (HS) in chicken myocardial cells, and it may be associated with heat shock proteins (HSPs). In this study, we further investigated the potential role of HSPs in the aspirin-induced heat stress resistance. Four of the most important HSPs including HspB1 (Hsp27), Hsp60, Hsp70, and Hsp90 were induced by aspirin pretreatment and were suppressed by BAPTA-AM. When HSPs were induced by aspirin, much slighter HS injury was detected. But more serious damages were observed when HSPs were suppressed by BAPTA-AM than those cells exposed to HS without BAPTA-AM, even the myocardial cells have been treated with aspirin in prior. Comparing to other HSPs, HspB1 presented the largest increase after aspirin treatments, 86-fold higher than the baseline (the level before HS). These findings suggested that multiple HSPs participated in aspirin’s anti-heat stress function but HspB1 may contribute the most. Interestingly, during the experiments, we also found that apoptosis rate as well as the oxidative stress indicators (T-SOD and MDA) was not consistently responding to heat stress injury as expected. By selecting from a series of candidates, myocardial cell damage-related enzymes (CK-MB and LDH), cytopathological tests, and necrosis rate (measured by flow cytometry assays) are believed to be reliable indicators to evaluate heat stress injury in chicken’s myocardial cells and they will be used in our further investigations. 相似文献
2.
Stéphanie Simon Valeriya Dimitrova Benjamin Gibert Sophie Virot Nicole Mounier Mathieu Nivon Carole Kretz-Remy Véronique Corset Patrick Mehlen André-Patrick Arrigo 《PloS one》2013,8(8)
Several human small heat shock proteins (sHsps) are phosphorylated oligomeric chaperones that enhance stress resistance. They are characterized by their ability to interact and form polydispersed hetero-oligomeric complexes. We have analyzed the cellular consequences of the stable expression of either wild type HspB5 or its cataracts and myopathies inducing R120G mutant in growing and oxidative stress treated HeLa cells that originally express only HspB1. Here, we describe that wild type and mutant HspB5 induce drastic and opposite effects on cell morphology and oxidative stress resistance. The cellular distribution and phosphorylation of these polypeptides as well as the oligomerization profile of the resulting hetero-oligomeric complexes formed by HspB1 with the two types of exogenous polypeptides revealed the dominant effects induced by HspB5 polypeptides towards HspB1. The R120G mutation enhanced the native size and salt resistance of HspB1-HspB5 complex. However, in oxidative conditions the interaction between HspB1 and mutant HspB5 was drastically modified resulting in the aggregation of both partners. The mutation also induced the redistribution of HspB1 phosphorylated at serine 15, originally observed at the level of the small oligomers that do not interact with wild type HspB5, to the large oligomeric complex formed with mutant HspB5. This phosphorylation stabilized the interaction of HspB1 with mutant HspB5. A dominant negative effect towards HspB1 appears therefore as an important event in the cellular sensitivity to oxidative stress mediated by mutated HspB5 expression. These observations provide novel data that describe how a mutated sHsp can alter the protective activity of another member of this family of chaperones. 相似文献
3.
White BG MacPhee DJ 《American journal of physiology. Regulatory, integrative and comparative physiology》2011,301(5):R1418-R1426
The uterine musculature, or myometrium, demonstrates tremendous plasticity during pregnancy under the influences of the endocrine environment and mechanical stresses. Expression of the small stress protein heat shock protein B1 (HspB1) has been reported to increase dramatically during late pregnancy, a period marked by myometrial hypertrophy caused by fetal growth-induced uterine distension. Thus, using unilaterally pregnant rat models and ovariectomized nonpregnant rats with uteri containing laminaria tents to induce uterine distension, we examined the effect of uterine distension on myometrial HspB1 expression. In unilaterally pregnant rats, HspB1 mRNA and Ser(15)-phosphorylated HspB1 (pSer(15) HspB1) protein expression were significantly elevated in distended gravid uterine horns at days 19 and 23 (labor) of gestation compared with nongravid horns. Similarly, pSer(15) HspB1 protein in situ was only readily detectable in the distended horns compared with the nongravid horns at days 19 and 23; however, pSer(15) HspB1 was primarily detectable in situ at day 19 in membrane-associated regions, while it had primarily a cytoplasmic localization in myometrial cells at day 23. HspB1 mRNA and pSer(15) HspB1 protein expression were also markedly increased in ovariectomized nonpregnant rat myometrium distended for 24 h with laminaria tents compared with empty horns. Therefore, uterine distension plays a major role in the stimulation of myometrial HspB1 expression, and increased expression of this small stress protein could be a mechanoadaptive response to the increasing uterine distension that occurs during pregnancy. 相似文献
4.
Heat shock proteins (Hsps) are highly conserved proteins that are induced in response to various physiological and environmental
stressors. HspB1 (Hsp27) is a prominent member of the small Hsps family and is strongly induced during the stress response.
Notably, HspB1 has powerful neuroprotective effects, increasing the survival of cells subjected to cytotoxic stimuli. This
is especially relevant to the study of the retina, where cells are subject to death due to retinal disease and injury. While
HspB1 shows constitutive expression in some areas of the mammalian retina, of particular interest is the upregulation of the
protein in response to ischemia and oxidative stress, traumatic nerve injury, and elevated intraocular pressure and glaucoma.
Several mechanisms have been proposed to account for the cytoprotective actions of HspB1, including its role as a molecular
chaperone, a stabilizer of the cytoskeleton, and a regulator of apoptosis. This review will focus on the role of HspB1 in
the retina, emphasizing effects on retinal ganglion cells, by analyzing the expression, induction by stressors, and mechanisms
of its neuroprotective function. Finally, the potential of HspB1 as a clinical therapeutic will be examined. 相似文献
5.
Previous studies have suggested that the small heat shock protein, HspB1, has a direct influence on the dynamics of cytoskeletal elements, in particular, filamentous actin (F-actin) polymerization. In this study we have assessed the influence of HspB1 phosphorylation on its interaction(s) with F-actin. We first determined the distribution of endogenous non-phosphorylated HspB1, phosphorylated HspB1 and F-actin in neuroendocrine PC12 cells by immunocytochemistry and confocal microscopy. We then investigated a potential direct interaction between HspB1 with F-actin by precipitating F-actin directly with biotinylated phalloidin followed by Western analyses; the reverse immunoprecipitation of HspB1 was also carried out. The phosphorylation influence of HspB1 in this interaction was investigated by using pharmacologic inhibition of p38 MAPK. In control cells, HspB1 interacts with F-actin as a predominantly non-phosphorylated protein, but subsequent to stress there is a redistribution of HspB1 to the cytoskeletal fraction and a significantly increased association of pHspB1 with F-actin. Our data demonstrate HspB1 is found in a complex with F-actin both in phosphorylated and non-phosphorylated forms, with an increased association of pHspB1 with F-actin after heat stress. Overall, our study combines both cellular and biochemical approaches to show cellular localization and direct demonstration of an interaction between endogenous HspB1 and F-actin using methodolgy that specifically isolates F-actin. 相似文献
6.
Upregulation of small heat-shock proteins (sHsps) in response to cellular stress is one mechanism to increase cell viability. We previously described that cultured rat hippocampal neurons express five of the 11 family members but only upregulate two of them (HspB1 and HspB5) at the protein level after heat stress. Since neurons have to cope with many other pathological conditions, we investigated in this study the expression of all five expressed sHsps on mRNA and protein level after sublethal sodium arsenite and oxidative and hyperosmotic stress. Under all three conditions, HspB1, HspB5, HspB6, and HspB8 but not HspB11 were consistently upregulated but showed differences in the time course of upregulation. The increase of sHsps always occurred earlier on mRNA level compared with protein levels. We conclude from our data that these four upregulated sHsps (HspB1, HspB5, HspB6, HspB8) act together in different proportions in the protection of neurons from various stress conditions. 相似文献
7.
Shu Tang Rehana Buriro Zhijun Liu Miao Zhang Islam Ali Abdelnasir Adam J?rg Hartung Endong Bao 《PloS one》2013,8(7)
Neonatal rat primary myocardial cells were subjected to heat stress in vitro, as a model for investigating the distribution and expression of Hsp27 and αB-crystallin. After exposure to heat stress at 42°C for different durations, the activities of enzymes expressed during cell damage increased in the supernatant of the heat-stressed myocardial cells from 10 min, and the pathological lesions were characterized by karyopyknosis and acute degeneration. Thus, cell damage was induced at the onset of heat stress. Immunofluorescence analysis showed stronger positive signals for both Hsp27 and αB-crystallin from 10 min to 240 min of exposure compared to the control cells. According to the Western blotting results, during the 480 min of heat stress, no significant variation was found in Hsp27 and αB-crystallin expression; however, significant differences were found in the induction of their corresponding mRNAs. The expression of these small heat shock proteins (sHsps) was probably delayed or overtaxed due to the rapid consumption of sHsps in myocardial cells at the onset of heat stress. Our findings indicate that Hsp27 and αB-crystallin do play a role in the response of cardiac cells to heat stress, but the details of their function remain to be investigated. 相似文献
8.
Britta Bartelt-Kirbach Alexander Slowik Cordian Beyer Nikola Golenhofen 《Cell stress & chaperones》2017,22(4):653-663
Ischemic stroke leads to cellular dysfunction, cell death, and devastating clinical outcomes. The cells of the brain react to such a cellular stress by a stress response with an upregulation of heat shock proteins resulting in activation of endogenous neuroprotective capacities. Several members of the family of small heat shock proteins (HspBs) have been shown to be neuroprotective. However, yet no systematic study examined all HspBs during cerebral ischemia. Here, we performed a comprehensive comparative study comprising all HspBs in an animal model of stroke, i.e., 1 h transient middle cerebral artery occlusion followed by 23 h of reperfusion. On the mRNA level out of the 11 HspBs investigated, HspB1/Hsp25, HspB3, HspB4/αA-crystallin, HspB5/αB-crystallin, HspB7/cvHsp, and HspB8/Hsp22 were significantly upregulated in the peri-infarct region of the cerebral cortex of infarcted hemispheres. HspB1 and HspB5 reached the highest mRNA levels and were also upregulated at the protein level, suggesting that these HspBs might be functionally most relevant. Interestingly, in the infarcted cortex, both HspB1 and HspB5 were mainly allocated to neurons and to a lesser extent to glial cells. Additionally, both proteins were found to be phosphorylated in response to ischemia. Our data suggest that among all HspBs, HspB1 and HspB5 might be most important in the neuronal stress response to ischemia/reperfusion injury in the brain and might be involved in neuroprotection. 相似文献
9.
Bryantsev AL Kurchashova SY Golyshev SA Polyakov VY Wunderink HF Kanon B Budagova KR Kabakov AE Kampinga HH 《The Biochemical journal》2007,407(3):407-417
In vitro, small Hsps (heat-shock proteins) have been shown to have chaperone function capable of keeping unfolded proteins in a form competent for Hsp70-dependent refolding. However, this has never been confirmed in living mammalian cells. In the present study, we show that Hsp27 (HspB1) translocates into the nucleus upon heat shock, where it forms granules that co-localize with IGCs (interchromatin granule clusters). Although heat-induced changes in the oligomerization status of Hsp27 correlate with its phosphorylation and nuclear translocation, Hsp27 phosphorylation alone is not sufficient for effective nuclear translocation of HspB1. Using firefly luciferase as a heat-sensitive reporter protein, we demonstrate that HspB1 expression in HspB1-deficient fibroblasts enhances protein refolding after heat shock. The positive effect of HspB1 on refolding is completely diminished by overexpression of Bag-1 (Bcl-2-associated athanogene), the negative regulator of Hsp70, consistent with the idea of HspB1 being the substrate holder for Hsp70. Although HspB1 and luciferase both accumulate in nuclear granules after heat shock, our results suggest that this is not related to the refolding activity of HspB1. Rather, granular accumulation may reflect a situation of failed refolding where the substrate is stored for subsequent degradation. Consistently, we found 20S proteasomes concentrated in nuclear granules of HspB1 after heat shock. We conclude that HspB1 contributes to an increased chaperone capacity of cells by binding unfolded proteins that are hereby kept competent for refolding by Hsp70 or that are sorted to nuclear granules if such refolding fails. 相似文献
10.
Fluorescent chimeras composed of enhanced cyan (or enhanced yellow) fluorescent proteins (ECFP or EYFP) and one of the four human small heat shock proteins (HspB1, HspB5, HspB6 or HspB8) were expressed in E. coli and purified. Fluorescent chimeras were used for investigation of heterooligomeric complexes formed by different small heat shock proteins (sHsp) and for analysis of their subunit exchange. EYFP-HspB1 and ECFP-HspB6 form heterooligomeric complex with apparent molecular weight of ∼280 kDa containing equimolar quantities of both sHsp. EYFP-HspB5 and ECFP-HspB6 formed heterogeneous oligomeric complexes. Fluorescent proteins inside heterooligomeric complexes formed by HspB1/HspB6 and HspB5/HspB6 chimeras are closely located, making possible effective fluorescence resonance energy transfer (FRET). Neither the wild type HspB8 nor its fluorescent chimeras were able to form stable heterooligomeric complexes with the wild type HspB1 and HspB5. Homo- and hetero-FRET was used for analysis of subunit exchange of small heat shock proteins. The apparent rate constant of subunit exchange was temperature-dependent and was higher for HspB6 forming small oligomers than for HspB1 forming large oligomers. Replacement induced by homologous subunits was more rapid than the replacement induced by heterologous subunits of small heat shock proteins. Fusion of fluorescent proteins might affect oligomeric structure of small heat shock proteins, however fluorescent chimeras can be useful for investigation of heterooligomeric complexes formed by sHsp and for analysis of kinetics of their subunit exchange. 相似文献
11.
Zhi-feng Liu Dong Zheng Guo-chang Fan Tianqing Peng Lei Su 《Apoptosis : an international journal on programmed cell death》2016,21(8):896-904
Pulmonary microvascular endothelial cells (PMECs) injury including apoptosis plays an important role in the pathogenesis of acute lung injury during sepsis. Our recent study has demonstrated that calpain activation contributes to apoptosis in PMECs under septic conditions. This study investigated how calpain activation mediated apoptosis and whether heat stress regulated calpain activation in lipopolysaccharides (LPS)-stimulated PMECs. In cultured mouse primary PMECs, incubation with LPS (1 μg/ml, 24 h) increased active caspase-3 fragments and DNA fragmentation, indicative of apoptosis. These effects of LPS were abrogated by pre-treatment with heat stress (43 °C for 2 h). LPS also induced calpain activation and increased phosphorylation of p38 MAPK. Inhibition of calpain and p38 MAPK prevented apoptosis induced by LPS. Furthermore, inhibition of calpain blocked p38 MAPK phosphorylation in LPS-stimulated PMECs. Notably, heat stress decreased the protein levels of calpain-1/2 and calpain activities, and blocked p38 MAPK phosphorylation in response to LPS. Additionally, forced up-regulation of calpain-1 or calpain-2 sufficiently induced p38 MAPK phosphorylation and apoptosis in PMECs, both of which were inhibited by heat stress. In conclusion, heat stress prevents LPS-induced apoptosis in PMECs. This effect of heat stress is associated with down-regulation of calpain expression and activation, and subsequent blockage of p38 MAPK activation in response to LPS. Thus, blocking calpain/p38 MAPK pathway may be a novel mechanism underlying heat stress-mediated inhibition of apoptosis in LPS-stimulated endothelial cells. 相似文献
12.
Oligomeric association of human small heat shock proteins HspB1, HspB5, HspB6 and HspB8 was analyzed by means of size-exclusion
chromatography, analytical ultracentrifugation and chemical cross-linking. Wild-type HspB1 and Cys mutants of HspB5, HspB6
and HspB8 containing a single Cys residue in position homologous to that of Cys137 of human HspB1 were able to generate heterodimers
cross-linked by disulfide bond. Cross-linked heterodimers between HspB1/HspB5, HspB1/HspB6 and HspB5/HspB6 were easily produced
upon mixing, whereas formation of any heterodimers with participation of HspB8 was significantly less efficient. The size
of heterooligomers formed by HspB1/HspB6 and HspB5/HspB6 was different from the size of the corresponding homooligomers. Disulfide
cross-linked homodimers of small heat shock proteins were unable to participate in heterooligomer formation. Thus, monomers
can be involved in subunit exchange leading to heterooligomer formation and restriction of flexibility induced by disulfide
cross-linking prevents subunit exchange. 相似文献
13.
Jonathan Crowe Anna Aubareda Kay McNamee Paulina M. Przybycien Xin Lu Richard O. Williams George Bou-Gharios Jeremy Saklatvala Jonathan L. E. Dean 《PloS one》2013,8(10)
There is large literature describing in vitro experiments on heat shock protein (hsp)B1 but understanding of its function in vivo is limited to studies in mice overexpressing human hspB1 protein. Experiments in cells have shown that hspB1 has chaperone activity, a cytoprotective role, regulates inflammatory gene expression, and drives cell proliferation. To investigate the function of the protein in vivo we generated hspB1-deficient mice. HspB1-deficient fibroblasts display increased expression of the pro-inflammatory cytokine, interleukin-6, compared to wild-type cells, but reduced proliferation. HspB1-deficient fibroblasts exhibit reduced entry into S phase and increased expression of cyclin-dependent kinase inhibitors p27kip1 and p21waf1. The expression of hspB1 protein and mRNA is also controlled by the cell cycle. To investigate the physiological function of hspB1 in regulating inflammation and cell proliferation we used an excisional cutaneous wound healing model. There was a significant impairment in the rate of healing of wounds in hspB1-deficient mice, characterised by reduced re-epithelialisation and collagen deposition but also increased inflammation. HspB1 deficiency augments neutrophil infiltration in wounds, driven by increased chemokine (C-X-C motif) ligand 1 expression. This appears to be a general mechanism as similar results were obtained in the air-pouch and peritonitis models of acute inflammation. 相似文献
14.
Catherine Paul Stéphanie Simon Benjamin Gibert Sophie Virot André-Patrick Arrigo 《Experimental cell research》2010,316(9):1535-818
Human HspB1 (also denoted Hsp27) is an oligomeric anti-apoptotic protein that has tumorigenic and metastatic roles. To approach the structural organizations of HspB1 that are active in response to apoptosis inducers acting through different pathways, we have analyzed the relative protective efficiency induced by this protein as well its localization, oligomerization and phosphorylation. HeLa cells, that constitutively express high levels of HspB1 were treated with either etoposide, Fas agonist antibody, staurosporine or cytochalasin D. Variability in HspB1 efficiency to interfere with the different apoptotic transduction pathways induced by these agents were detected. Moreover, inducer-specific dynamic changes in HspB1 localization, native size and phosphorylation were observed, that differed from those observed after heat shock. Etoposide and Fas treatments gradually shifted HspB1 towards large but differently phosphorylated oligomeric structures. In contrast, staurosporine and cytochalasin D induced the rapid but transient formation of small oligomers before large structures were formed. These events correlated with inducer-specific phosphorylations of HspB1. Of interest, the formation of small oligomers in response to staurosporine and cytochalasin D was time correlated with the rapid disruption of F-actin. The subsequent, or gradual in the case of etoposide and Fas, formation of large oligomeric structures was a later event concomitant with the early phase of caspase activation. These observations support the hypothesis that HspB1 has the ability, through specific changes in its structural organization, to adapt and interfere at several levels with challenges triggered by different signal transduction pathways upstream of the execution phase of apoptosis. 相似文献
15.
Bacterial endotoxin lipopolysaccharide (LPS) induces the production of inflammatory cytokines and reactive oxygen species (ROS) under in vivo and in vitro conditions. Acetylsalicylic acid (ASA, aspirin) is a commonly used anti-inflammatory drug. Our aim was to study the effects of N-acetyl cysteine (NAC), an antioxidant precursor of GSH synthesis, on aspirin-sensitized macrophages treated with LPS. We investigated the effects of LPS alone and in conjunction with a sub-toxic concentration of ASA, on metabolic and oxidative stress, apoptosis, and mitochondrial function using J774.2 mouse macrophage cell line. Protection from LPS-induced toxicity by NAC was also studied. LPS alone markedly induced ROS production and oxidative stress in macrophage cells. When ASA was added to LPS-treated macrophages, the increase in oxidative stress was significantly higher than that with LPS alone. Similarly, alteration in glutathione-dependent redox metabolism was also observed in macrophages after treatment with LPS and ASA. The combination of LPS and ASA selectively altered the CYP 3A4, CYP 2E1 and CYP 1A1 catalytic activities. Mitochondrial respiratory complexes and ATP production were also inhibited by LPS-ASA treatment. Furthermore a higher apoptotic cell death was also observed in LPS-ASA treated macrophages. NAC pre-treatment showed protection against oxidative stress induced apoptosis and mitochondrial dysfunction. These effects are presumed, at least in part, to be associated with alterations in NF-κB/Nrf-2 mediated cell signaling. These results suggest that macrophages are more sensitive to LPS when challenged with ASA and that NAC pre-treatment protects the macrophages from these deleterious effects. 相似文献
16.
Thomas Schmidt Dietmar Fischer Anastasia Andreadaki Britta Bartelt-Kirbach Nikola Golenhofen 《Cell stress & chaperones》2016,21(1):167-178
Several eye diseases are associated with axonal injury in the optic nerve, which normally leads to degeneration of retinal ganglion cells (RGCs) and subsequently to loss of vision. There is experimental evidence that some members of the small heat shock protein family (HspBs) are upregulated upon optic nerve injury (ONI) in the retina and sufficient to promote RGC survival. These data raise the question as to whether other family members may play a similar role in this context. Here, we performed a comprehensive comparative study comprising all HspBs in an experimental model of ONI. We found that five HspBs were expressed in the adult rat retina at control conditions but only HspB1 and HspB5 were upregulated in response to ONI. Furthermore, HspB1 and HspB5 were constitutively phosphorylated in Müller cells at serine 15 and serine 59, respectively. In RGCs, phosphorylation was stimulated by ONI and occurred at serine 86 of HspB1 and at serine 19 and 45 of HspB5. These data suggest that of all small heat shock proteins, only HspB1 and HspB5 might be of protective value for RGCs after ONI and that this process might be regulated by phosphorylation at serine 86 of HspB1 and serine 19 and serine 45 of HspB5. The molecular targets of phosphoHspB1 and phosphoHspB5 remain to be identified.
Electronic supplementary material
The online version of this article (doi:10.1007/s12192-015-0650-8) contains supplementary material, which is available to authorized users. 相似文献17.
The so-called stress response involving upregulation of heat shock proteins (Hsps) is a powerful mechanism of cells to deal with harmful conditions to which they are exposed throughout life, such as hyperthermia, hypoxia or oxidative stress. To gain more information about the molecular targets by which HspB1 (Hsp25) and HspB5 (αB-crystallin) might exert their neuroprotective effect we investigated the subcellular localization of unphosphorylated and phosphorylated HspB1 and B5 in neurons by immunocytochemistry and subcellular fractionation. In cultured hippocampal neurons, the unphosphorylated forms of both Hsps were localized in the perikaryon and nucleus, whereas the phosphorylated forms were recruited into neuronal processes. pHspB1-Ser15 and -Ser 86 were found within dendrites with a punctate distribution pattern partially colocalizing with the synaptic marker vGlut-1. pHspB5-Ser19 and -Ser45 localized to axons and dendrites with a filamentous-like staining pattern, whereas pHspB5-Ser59 was found in dendrites, especially along the plasma membrane and in spines. Biochemical analysis, i.e. subcellular fractionation of rat brain with subsequent Western blotting supported these localizations. These data show that in neurons HspB1 and B5 may have various molecular interaction partners at synapses, within dendrites and axons and that this interaction is likely to be regulated by phosphorylation. Stress-induced phosphorylation of HspB1 and B5 may lead to binding of these Hsps to their targets at synapses and neuronal processes which might provide one important mechanism of how they exert their neuroprotective effect. 相似文献
18.
Victoria V. Nefedova Maria V. Sudnitsyna Nikolai B. Gusev 《Cell stress & chaperones》2017,22(4):467-479
The interaction of human small heat shock protein HspB1, its point mutants associated with distal hereditary motor neuropathy, and three other small heat shock proteins (HspB5, HspB6, HspB8) with the light component of neurofilaments (NFL) was analyzed by differential centrifugation, analytical ultracentrifugation, and fluorescent spectroscopy. The wild-type HspB1 decreased the quantity of NFL in pellets obtained after low- and high-speed centrifugation and increased the quantity of NFL remaining in the supernatant after high-speed centrifugation. Part of HspB1 was detected in the pellet of NFL after high-speed centrifugation, and at saturation, 1 mol of HspB1 monomer was bound per 2 mol of NFL. Point mutants of HspB1 associated with distal hereditary motor neuropathy (G84R, L99M, R140G, K141Q, and P182S) were almost as effective as the wild-type HspB1 in modulation of NFL assembly. At low ionic strength, HspB1 weakly interacted with NFL tetramers, and this interaction was increased upon salt-induced polymerization of NFL. HspB1 and HspB5 (αB-crystallin) decreased the rate of NFL polymerization measured by fluorescent spectroscopy. HspB6 (Hsp20) and HspB8 (Hsp22) were less effective than HspB1 (or HspB5) in modulation of NFL assembly. The data presented indicate that the small heat shock proteins affect NFL transition from tetramers to filaments, hydrodynamic properties of filaments, and their bundling and therefore probably modulate the formation of intermediate filament networks in neurons. 相似文献
19.
Verschuure P Tatard C Boelens WC Grongnet JF David JC 《European journal of cell biology》2003,82(10):523-530
Recently, we have described the developmental expression of the small heat shock proteins (sHsps) Hsp27/HspB1 and alphaB-crystallin/HspB5 in different tissues of pigs from almost full-term foetuses to three years old adults (P. Tallot, J. F. Grongnet, J. C. David, Biol. Neonate, 83, 281-288, 2003). The data described in this report extends this study to four other members of the sHsp family (Hsp20/HspB6, cvHsp/HspB7, MKBP/HspB2 and HspB8). We studied expression of these proteins in porcine lens, brain, heart, liver, kidney, lung, skeletal muscle, stomach, and colon, and found a ubiquitous expression of Hsp20 and HspB8 as earlier reported for Hsp27 and alphaB-crystallin. In contrast, cvHsp and HspB2 expression is essentially restricted to heart and muscle. During development, the sHsps tend to (temporarily) increase in stomach, liver, lung, kidney, hippocampus, and striatum, while expression in heart is more or less constant, and a large variation is found in sHsp expression patterns in skeletal muscle. In cerebellum and cortex a temporary decrease of Hsp20 and HspB8 is observed directly after birth. The major impact of this study is that each tissue seems to have a unique profile of sHsp expression, which varies during development and may reflect the need of a particular tissue to maintain at all stages an optimal chaperoning machinery to protect against physiological stress. 相似文献
20.
Regulatory interfaces between the stress protein response and other gene expression programs in the cell 总被引:2,自引:0,他引:2
Calderwood SK 《Methods (San Diego, Calif.)》2005,35(2):139-148
The stress protein response involves the immediate reprogramming of gene expression in cells exposed to proteomic insult leading to massive synthesis of heat shock proteins (HSP). We have examined the outcome when cells are induced to activate two other gene expression programs--the acute inflammatory response and entry of quiescent cells into the cell cycle--and then exposed to protein stress. We find that these responses are mutually antagonistic with, on the one hand, heat shock factor 1 (HSF1) inhibition through the phosphorylation of inhibitory serine residues after inflammatory or mitogenic stimulus and, on the other hand, after stress, HSF1 directly repressing the promoters of genes that mediate acute inflammation and mitogenesis. The expression of the stress protein response during periods of acute protein damage was shown to lead to efficient activation of HSF1 and HSP expression accompanied by repression of other gene expression programs. 相似文献