Search results for "Hsp"

Human chaperonin disease-causing mutations: study with a prokaryotic model.

2012

Myelin pathology: Involvement of molecular chaperones and the promise of chaperonotherapy

2019

The process of axon myelination involves various proteins including molecular chaperones. Myelin alteration is a common feature in neurological diseases due to structural and functional abnormalities of one or more myelin proteins. Genetic proteinopathies may occur either in the presence of a normal chaperoning system, which is unable to assist the defective myelin protein in its folding and migration, or due to mutations in chaperone genes, leading to functional defects in assisting myelin maturation/migration. The latter are a subgroup of genetic chaperonopathies causing demyelination. In this brief review, we describe some paradigmatic examples pertaining to the chaperonins Hsp60 (HSPD1,…

Stress response in mesoangioblast stem cells

2006

Stem cells are presumed to survive various stresses, since they are recruited to areas of tissue damage and regeneration, where inflammatory cytokines and cytotoxic cells may result in severe cell injury. We explored the ability of mesoangioblasts to respond to different cell stresses such as heat, heavy metals and osmotic stress, by analyzing heat shock protein (HSP)70 synthesis as a stress indicator. We found that the A6 mesoangioblast stem cells constitutively synthesize HSP70 in a heat shock transcription factor (HSF)-independent way. However, A6 respond to heat shock and cadmium treatment by synthesizing HSP70 over the constitutive expression and this synthesis is HSF1 dependent. The e…

Endoplasmic reticulum‐resident chaperones modulate the inflammatory and angiogenic responses of endothelial cells

2015

SummaryBackground Wound healing depends on a well-balanced regulation of inflammation and angiogenesis. In chronic wounds the healing process is disturbed and inflammation persists. Regulation of wound closure is controlled by transmembrane and extracellular proteins, the folding and maturation of which occur in the endoplasmic reticulum (ER) by ER-resident chaperone machinery. Objectives To study the role of the ER-resident chaperones BiP/Grp78, its cochaperone Mdg1/ERdJ4, and Grp94 in chronic, nonhealing wounds. Methods Immunohistochemical staining of these chaperones in individual human biopsies and investigation of the possible role of BiP and Mdg1 in endothelial cells, focusing on thei…

Hsp60 molecular anatomy and role in colorectal cancer diagnosis and treatment

2011

Quantitative changes in Hsp60 during the development of some tumors suggest that this chaperonin plays a role in carcinogenesis. A description of the specific role(s) of Hsp60 in tumor-cell growth and proliferation is still incomplete, but it is already evident that monitoring its levels and distribution in tissues and fluids has potential for diagnosis and staging, and for assessing prognosis and response to treatment. Although Hsp60 is considered an intramitochondrial protein, it has been demonstrated in the cytosol, cell membrane, vesicles, cell surface, extracellular space, and blood. The knowledge that Hsp60 occurs at all these locations opens new avenues for basic and applied research…

Mitochondrial compartment: a possible target of cadmium effects on breast epithelial cells.

2009

Cadmium–breast epithelial cell interactions were studied by analyzing some mitochondria-related aspects of stress response. We treated immortalized non-tumor breast cells with 5 or 50 μM CdCl2 for 24 or 96 h demonstrating that the exposure did not cause a significant mitochondrial proliferation, while it induced a significant increase in the respiratory activity and mitochondrial polarization. In addition, we found that hsp60 was up-regulated while hsp70 and COXII and COXIV were down-regulated. The mRNA for hsp70 remained constant and only the inducible form of the 70-kDa heat shock protein was over expressed. The mRNAs for COXII and COXIV remained constant after 24 h and increased after lo…

Heat shock and Cd2+ exposure regulate PML and Daxx release from ND10 by independent mechanisms that modify the induction of heat-shock proteins 70 an…

2003

Nuclear domains called ND10 or PML bodies might function as nuclear depots by recruiting or releasing certain proteins. Although recruitment of proteins through interferon-induced upregulation and SUMO-1 modification level of PML had been defined, it is not known whether release of proteins is regulated and has physiological consequences. Exposure to sublethal environmental stress revealed a sequential release of ND10-associated proteins. Upon heat shock Daxx and Sp100 were released but PML remained, whereas exposure to subtoxic concentrations of CdCl2 induced the release of ND10-associated proteins, including PML, with Sp100 remaining in a few sites. In both cases,recovery times were simil…

Multimodal Tasks for Translators: A Translational Dialogue with Cia Rinne and Her Work

2021

Decipher the mechanisms of protein conformational changes induced by nucleotide binding through free-energy landscape analysis: ATP binding to Hsp70.

2013

ATP regulates the function of many proteins in the cell by transducing its binding and hydrolysis energies into protein conformational changes by mechanisms which are challenging to identify at the atomic scale. Based on molecular dynamics (MD) simulations, a method is proposed to analyze the structural changes induced by ATP binding to a protein by computing the effective free-energy landscape (FEL) of a subset of its coordinates along its amino-acid sequence. The method is applied to characterize the mechanism by which the binding of ATP to the nucleotide-binding domain (NBD) of Hsp70 propagates a signal to its substrate-binding domain (SBD). Unbiased MD simulations were performed for Hsp…

A constitutive 70 kDa heat-shock protein is localized on the fibres of spindles and asters at metaphase in an ATP-dependent manner: A new chaperone r…

2001

In the present study, double immunofluorescence and immunoblot analysis have been used to show that centrosomes, isolated from Paracentrotus lividus sea urchin embryos at the first mitotic metaphase, contain the constitutive chaperone, heat-shock protein (HSP) 70. More specifically, we demonstrate that centrosomes contain only the HSP70-d isoform, which is one of the four isoforms identified in P. lividus . We also provide evidence that p34(cell division control kinase-2) and t complex polypeptide-1 (TCP-1) α, a subunit of the TCP-1 complex, are localized on the centrosomes. Furthermore, inhibition of TCP-1 in vivo, via microinjecting an anti-(TCP-1α) antibody into P. lividus eggs before fe…