Search results for "Molecular chaperones."
showing 10 items of 61 documents
AtCCS is a functional homolog of the yeast copper chaperone Ccs1/Lys7
2005
AbstractIn plant chloroplasts two superoxide dismutase (SOD) activities occur, FeSOD and Cu/ZnSOD, with reciprocal regulation in response to copper availability. This system presents a unique model to study the regulation of metal-cofactor delivery to an organelle. The Arabidopsis thaliana gene AtCCS encodes a functional homolog to yeast Ccs1p/Lys7p, a copper chaperone for SOD. The AtCCS protein was localized to chloroplasts where it may supply copper to the stromal Cu/ZnSOD. AtCCS mRNA expression levels are upregulated in response to Cu-feeding and senescence. We propose that AtCCS expression is regulated to allow the most optimal use of Cu for photosynthesis.
Prefoldins contribute to maintaining the levels of the spliceosome LSM2–8 complex through Hsp90 in Arabidopsis
2020
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In vivoanalysis of the lumenal binding protein (BiP) reveals multiple functions of its ATPase domain
2007
International audience; The endoplasmic reticulum (ER) chaperone binding protein (BiP) binds exposed hydrophobic regions of misfolded proteins. Cycles of ATP hydrolysis and nucleotide exchange on the ATPase domain were shown to regulate the function of the ligand-binding domain in vitro. Here we show that ATPase mutants of BiP with defective ATP-hydrolysis (T46G) or ATP-binding (G235D) caused permanent association with a model ligand, but also interfered with the production of secretory, but not cytosolic, proteins in vivo. Furthermore, the negative effect of BiP(T46G) on secretory protein synthesis was rescued by increased levels of wild-type BiP, whereas the G235D mutation was dominant. U…
Hsp60, amateur chaperone in amyloid-beta fibrillogenesis
2016
BACKGROUND: Molecular chaperones are a very special class of proteins that play essential roles in many cellular processes like folding, targeting and transport of proteins. Moreover, recent evidence indicates that chaperones can act as potentially strong suppressor agents in Alzheimer's disease (AD). Indeed, in vitro experiments demonstrate that several chaperones are able to significantly slow down or suppress aggregation of Aβ peptide and in vivo studies reveal that treatment with specific chaperones or their overexpression can ameliorate some distinct pathological signs characterizing AD. METHODS: Here we investigate using a biophysical approach (fluorescence, circular dichroism (CD), t…
Alzheimer's Disease and Molecular Chaperones: Current Knowledge and the Future of Chaperonotherapy
2016
Background: Alzheimer’s disease (AD) is a dementia, a neurodegenerative condition, and a protein-misfolding disease or proteinopathy, characterized by protein deposits, extracellular plaques and intracellular neurofibrillary tangles, which contain the AD’s typical pathological proteins, abnormal [1]-amyloid and hyperphosphorylated tau, respectively, and are located predominantly in the cortex of the frontal, parietal, and temporal brain lobes. What is the role of molecular chaperones in AD? Data indicate that molecular chaperones, also known as Hsp, are involved in AD, probably displaying protective roles and/or acting as pathogenic factors as it occurs in chaperonopathies in which case AD …
The neurochaperonopathies: Anomalies of the chaperone system with pathogenic effects in neurodegenerative and neuromuscular disorders
2021
The chaperone (or chaperoning) system (CS) constitutes molecular chaperones, co-chaperones, and chaperone co-factors, interactors and receptors, and its canonical role is protein quality control. A malfunction of the CS may cause diseases, known as the chaperonopathies. These are caused by qualitatively and/or quantitatively abnormal molecular chaperones. Since the CS is ubiquitous, chaperonopathies are systemic, affecting various tissues and organs, playing an etiologic-pathogenic role in diverse conditions. In this review, we focus on chaperonopathies involved in the pathogenic mechanisms of diseases of the central and peripheral nervous systems: the neurochaperonopathies (NCPs). Genetic …
Exosomal Chaperones and miRNAs in Gliomagenesis: State-of-Art and Theranostics Perspectives
2018
Gliomas have poor prognosis no matter the treatment applied, remaining an unmet clinical need. As background for a substantial change in this situation, this review will focus on the following points: (i) the steady progress in establishing the role of molecular chaperones in carcinogenesis; (ii) the recent advances in the knowledge of miRNAs in regulating gene expression, including genes involved in carcinogenesis and genes encoding chaperones; and (iii) the findings about exosomes and their cargo released by tumor cells. We would like to trigger a discussion about the involvement of exosomal chaperones and miRNAs in gliomagenesis. Chaperones may be either targets for therapy, due to their…
Human molecular chaperones share with SARS-CoV-2 antigenic epitopes potentially capable of eliciting autoimmunity against endothelial cells: possible…
2020
Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), the cause of COVID-19 disease, has the potential to elicit autoimmunity because mimicry of human molecular chaperones by viral proteins. We compared viral proteins with human molecular chaperones, many of which are heat shock proteins, to determine if they share amino acid-sequence segments with immunogenic-antigenic potential, which can elicit cross-reactive antibodies and effector immune cells with the capacity to damage-destroy human cells by a mechanism of autoimmunity. We identified the chaperones that can putatively participate in molecular mimicry phenomena after SARS-CoV-2 infection, focusing on those for which endotheli…
Circulating Molecular Chaperones in Subjects with Amnestic Mild Cognitive Impairment and Alzheimer’s Disease: Data from the Zabùt Aging Project
2022
Molecular chaperones play essential roles in many processes such as cell differentiation, tissue homeostasis, and organ remodeling. Recent data indicate that chaperones can act as cytoprotectants for brain cells during the progression of neurodegenerative diseases, including Alzheimer’s disease (AD). However, very few data on the levels of chaperones in dementia, including its prodromal phases, have been reported. In this study, we used biological samples and epidemiological data collected during the Zabùt Aging Project (a prospective, community-based, cohort study of normal/pathological aging conducted in Sicily, Italy, with a follow-up of ten years) to determine if there is an association…
Functions and Therapeutic Potential of Extracellular Hsp60, Hsp70, and Hsp90 in Neuroinflammatory Disorders
2021
Neuroinflammation is implicated in central nervous system (CNS) diseases, but the molecular mechanisms involved are poorly understood. Progress may be accelerated by developing a comprehensive view of the pathogenesis of CNS disorders, including the immune and the chaperone systems (IS and CS). The latter consists of the molecular chaperones; cochaperones; and chaperone cofactors, interactors, and receptors of an organism and its main collaborators in maintaining protein homeostasis (canonical function) are the ubiquitin–proteasome system and chaperone-mediated autophagy. The CS has also noncanonical functions, for instance, modulation of the IS with induction of proinflammatory cytokines. …