Search results for "Chaperones"
showing 10 items of 127 documents
Protein Kinase C μ Is Regulated by the Multifunctional Chaperon Protein p32
2000
We identified the multifunctional chaperon protein p32 as a protein kinase C (PKC)-binding protein interacting with PKCalpha, PKCzeta, PKCdelta, and PKC mu. We have analyzed the interaction of PKC mu with p32 in detail, and we show here in vivo association of PKC mu, as revealed from yeast two-hybrid analysis, precipitation assays using glutathione S-transferase fusion proteins, and reciprocal coimmunoprecipitation. In SKW 6.4 cells, PKC mu is constitutively associated with p32 at mitochondrial membranes, evident from colocalization with cytochrome c. p32 interacts with PKC mu in a compartment-specific manner, as it can be coimmunoprecipitated mainly from the particulate and not from the so…
Dissection of human papillomavirus type 33 L2 domains involved in nuclear domains (ND) 10 homing and reorganization
2003
Abstract We have recently shown that the minor capsid protein L2 of human papillomavirus type 33 (HPV33) recruits the transcriptional repressor Daxx into nuclear domains (ND) 10 and causes the loss of the transcriptional activator Sp100 from these subnuclear structures (Florin et al., 2002b) . In order to dissect L2 domains involved in nuclear translocation, ND10 homing, loss of Sp100, and recruitment of Daxx, a detailed deletion mutagenesis of L2 was performed. Using immunofluorescence and green fluorescent protein fusions, we have identified two nuclear localization signals (NLS) in the central and C-terminal part of L2, respectively, homologous to previously identified NLS in HPV6B L2 (S…
Hsp10: Anatomic distribution, functions, and involvement in human disease
2013
There is growing evidence that molecular chaperones/heat shock proteins are involved in the pathogenesis of a number of human diseases, known as chaperonopathies. A better molecular understanding of the pathogenetic mechanisms is essential for addressing new strategies in diagnostics, therapeutics and clinical management of chaperonopathies, including those in which Hsp10 is involved. This chaperonin has been studied for a long time as a member of the mitochondrial protein-folding machine. However, although in normal cells Hsp10 is mainly localized in the mitochondrial matrix, it has also been found during and after stress in other subcellular compartments, such as cytosol, vesicles and sec…
Contribution of Extracellular Vesicles and Molecular Chaperones in Age-Related Neurodegenerative Disorders of the CNS
2023
Many neurodegenerative disorders are characterized by the abnormal aggregation of misfolded proteins that form amyloid deposits which possess prion-like behavior such as self-replication, intercellular transmission, and consequent induction of native forms of the same protein in surrounding cells. The distribution of the accumulated proteins and their correlated toxicity seem to be involved in the progression of nervous system degeneration. Molecular chaperones are known to maintain proteostasis, contribute to protein refolding to protect their function, and eliminate fatally misfolded proteins, prohibiting harmful effects. However, chaperone network efficiency declines during aging, prompt…
HSP27 controls GATA-1 protein level during erythroid cell differentiation.
2010
AbstractHeat shock protein 27 (HSP27) is a chaperone whose cellular expression increases in response to various stresses and protects the cell either by inhibiting apoptotic cell death or by promoting the ubiquitination and proteasomal degradation of specific proteins. Here, we show that globin transcription factor 1 (GATA-1) is a client protein of HSP27. In 2 models of erythroid differentiation; that is, in the human erythroleukemia cell line, K562 induced to differentiate into erythroid cells on hemin exposure and CD34+ human cells ex vivo driven to erythroid differentiation in liquid culture, depletion of HSP27 provokes an accumulation of GATA-1 and impairs terminal maturation. More spec…
Decoding the Folding of Burkholderia glumae Lipase: Folding Intermediates En Route to Kinetic Stability
2012
The lipase produced by Burkholderia glumae folds spontaneously into an inactive near-native state and requires a periplasmic chaperone to reach its final active and secretion-competent fold. The B. glumae lipase-specific foldase (Lif) is classified as a member of the steric-chaperone family of which the propeptides of alpha-lytic protease and subtilisin are the best known representatives. Steric chaperones play a key role in conferring kinetic stability to proteins. However, until present there was no solid experimental evidence that Lif-dependent lipases are kinetically trapped enzymes. By combining thermal denaturation studies with proteolytic resistance experiments and the description of…
Immunomorphological Pattern of Molecular Chaperones in Normal and Pathological Thyroid Tissues and Circulating Exosomes: Potential Use in Clinics
2019
The thyroid is a major component of the endocrine system and its pathology can cause serious diseases, e.g., papillary carcinoma (PC). However, the carcinogenic mechanisms are poorly understood and clinical useful biomarkers are scarce. Therefore, we determined if there are quantitative patterns of molecular chaperones in the tumor tissue and circulating exosomes that may be useful in diagnosis and provide clues on their participation in carcinogenesis. Hsp27, Hsp60, Hsp70, and Hsp90 were quantified by immunohistochemistry in PC, benign goiter (BG), and normal peritumoral tissue (PT). The same chaperones were assessed in plasma exosomes from PC and BG patients before and after ablative surg…
Chaperone patterns in vernal keratoconjunctivitis are distinctive of cell and Hsp type and are modified by inflammatory stimuli
2016
Background Vernal keratoconjunctivitis (VKC) is a severe ocular allergy with pathogenic mechanism poorly understood and no efficacious treatment. The aims of the study were to determine quantities and distribution of Hsp chaperones in the conjunctiva of VKC patients and assess their levels in conjunctival epithelial and fibroblast cultures exposed to inflammatory stimuli. Methods Hsp10, Hsp27, Hsp40, Hsp60, Hsp70, Hsp90, Hsp105, and Hsp110 were determined in conjunctiva biopsies from nine patients and nine healthy age-matched normal subjects, using immunomorphology and qPCR. Conjunctival epithelial cells and fibroblasts were cultured and stimulated with IL-1β, histamine, IL-4, TNF-α, or UV-…
The expression of HSP27 is associated with poor clinical outcome in intrahepatic cholangiocarcinoma.
2007
Abstract Background The heat shock proteins (HSPs) 27-kDa (HSP27) and 72-kDa (HSP72), are ubiquitous chaperone molecules inducible in cells exposed to different stress conditions. Increased level of HSPs are reported in several human cancers, and found to be associated with the resistance to some anticancer treatments and poor prognosis. However, there is no study of the relationship between HSPs expression and patient's prognosis in intrahepatic cholangiocarcinoma (IHCCA). In this exploratory retrospective study, we investigated the expressions of HSP27 and HSP72 as potential prognostic factors in IHCCA. Methods Thirty-one paraffin-embedded samples were analyzed by immunohistochemical meth…
X-linked primary ciliary dyskinesia due to mutations in the cytoplasmic axonemal dynein assembly factor PIH1D3
2017
By moving essential body fluids and molecules, motile cilia and flagella govern respiratory mucociliary clearance, laterality determination and the transport of gametes and cerebrospinal fluid. Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder frequently caused by non-assembly of dynein arm motors into cilia and flagella axonemes. Before their import into cilia and flagella, multi-subunit axonemal dynein arms are thought to be stabilized and pre-assembled in the cytoplasm through a DNAAF2–DNAAF4–HSP90 complex akin to the HSP90 co-chaperone R2TP complex. Here, we demonstrate that large genomic deletions as well as point mutations involving PIH1D3 are responsible for an X-li…