Article

Identification of a novel member of mouse hsp70 family. Its association with cellular phenotype

Toyota Physical and Chemical Institute, Seto, Aichi, Japan
Journal of Biological Chemistry (Impact Factor: 4.57). 04/1993; 268(9):6615-21.
Source: PubMed

ABSTRACT

A novel 66-kDa protein, named p66mot-1, is identified to be associated with cellular mortality by virtue of its presence in cytosolic fractions of serially passaged mouse embryonic fibroblasts (MEF) and the mortal hybrids obtained by the fusion of mortal (MEF) and immortal (MN48-1, derivative of NIH 3T3) cells. Immortal cells lack this protein in their cytosolic fractions. cDNA cloning and homology search placed it in the heat shock protein 70 (hsp70) family. Microinjection of anti-p66 antibody to senescent MEF could transiently stimulate their cell division, which supports the cellular mortality-related function of p66mot-1.

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    • "HSPA8 is an essential housekeeping gene [28] involved in clinical diseases including, cancer, cardiovascular, neurological, and hepatic disorders [29]. A third HSP70 family member, HSPA9, was originally discovered for its contribution to cellular mortality in mouse embryonic fibroblasts (MEFs), by analyzing the cytosolic fraction of serially passaged MEFs [30] [31]. Since then, it has been shown that HSPA9 changes its subcellular localization from the mitochondria, in normal cells, to the cytosol in neoplastic cells [32]. "
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    ABSTRACT: Heat shock proteins (HSP) perform vital cellular functions and modulate cell response pathways to physical and chemical stressors. A key feature of HSP function is the ability to interact with a broad array of protein binding partners as a means to potentiate downstream response pathways or facilitate protein folding. These binding interactions are driven by ATP-dependent conformational rearrangements in HSP proteins. The HSP70 family is evolutionarily conserved and is associated with diabetes and cancer progression and the etiopathogenesis of hepatic, cardiovascular, and neurological disorders in humans. However, functional characterization of human HSP70s has been stymied by difficulties in obtaining large quantities of purified protein. Studies of purified human HSP70 proteins are essential for downstream investigations of protein–protein interactions and in the rational design of novel family-specific therapeutics. Within this work, we present optimized protocols for the heterologous overexpression and purification of either the nucleotide binding domain (NBD) or the nucleotide and substrate binding domains of human HSPA9, HSPA8, and HSPA5in either Escherichiacoli or Saccharomycescerevisiae. We also include initial biophysical characterization of HSPA9 and HSPA8.This work provides the basis for future biochemical studies of human HSP70 protein function and structure.
    Full-text · Article · Sep 2014 · Protein Expression and Purification
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    • "It is interesting to note that the trajectory of our understanding on the cellular roles of mortalin is quite unlike the way other Hsp70s have gone (Kaul et al. 2007). Other chaperones was seen as only helpers in maintaining proteome integrity, however, mortalin was initially discovered as a " mortality " associated gene (Wadhwa et al. 1993a), a stress-associated protein targeted by toxicants (Bruschi et al. 1993), then as an antigen-processing protein (Domanico et al. 1993) and finally as the main motor component for mitochondrial biogenesis (Webster et al. 1994). Unexpectedly , mortalin has been shown participate in regulating the dynamic organization of the cytoskeleton (Cicchillitti et al. 2009) and in cellular uptake mechanisms via the lipid rafts (Wittrup et al. 2010). "
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    ABSTRACT: Mortalin/mtHsp70 performs a wide array of cellular functions and has been implicated in aging, cancer and neurodegenerative diseases. Similar to other Hsp70s, its ability to chaperone misfolded proteins and bind to a myriad of clients is derived from its N-terminal nucleotide-binding domain (NBD) regulating substrate affinity of the C-terminal substrate-binding domain (SBD) in a nucleotide- and co-chaperone-dependent mechanism. To understand the structural dynamics of its allostery making this relevant to mortalin's cellular function, this chapter describes key structural features of these two domains as well as provide an appreciation as to possibly how a single amino acid change, Gly to Arg in the SBD that can be viewed so minor, is able to metamorphose from a life-extending species of mortalin (mot-2) into one that induces senescence and even inhibits tumor growth (mot-1).
    Full-text · Article · Apr 2014
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    • "We found 5 protein spots specifically identified by the anti-HCF serum. These proteins were analyzed by MALDI TOF/TOF-MS, and two of them were identified as mortalin [14] and creatine kinase M-type (EC = 2.7.3.2). Exploring the E. granulosus nonredundant protein sequences data base (blastp, protein-protein BLAST), we did not found any significant homology between creatine kinase M-type and E. granulosus proteins. "
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    ABSTRACT: This study evaluates the antitumor immune response induced by human hydatic cyst fluid (HCF) in an animal model of colon carcinoma. We found that anti-HCF antibodies were able to identify cell surface and intracellular antigens in CT26 colon cancer cells. In prophylactic tumor challenge experiments, HCF vaccination was found to be protective against tumor formation for 40% of the mice (P = 0.01). In the therapeutic setting, HCF vaccination induced tumor regression in 40% of vaccinated mice (P = 0.05). This vaccination generated memory immune responses that protected surviving mice from tumor rechallenge, implicating the development of an adaptive immune response in this process. We performed a proteomic analysis of CT26 antigens recognized by anti-HCF antibodies to analyze the immune cross-reactivity between E. granulosus (HCF) and CT26 colon cancer cells. We identified two proteins: mortalin and creatine kinase M-type. Interestingly, CT26 mortalin displays 60% homology with E. granulosus hsp70. In conclusion, our data demonstrate the capacity of HCF vaccination to induce antitumor immunity which protects from tumor growth in an animal model. This new antitumor strategy could open new horizons in the development of highly immunogenic anticancer vaccines.
    Full-text · Article · Aug 2013 · The Scientific World Journal
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