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HSP27 (also known as the Estrogen-Regulated 24K protein, and hsp 28) is a member of the mammalian small heat shock protein family. Hsp27 is expressed constitutively in many tissues and its expression is increased to high levels after various types of stress including elevated temperatures, toxic metals, drugs and oxidants. Also, Hsp27 is phosphorylated in vivo on three phosphorylation sites (Ser15, Ser78 and Ser82) by protein kinases including MAPKAP kinase 2 and the stress-activated protein kinase SAPK2 (p38).

Escherichia coli Hsp31 (HchA) is a homodimeric member of the ThiI/DJ-1/PfpI superfamily which combines molecular chaperone and aminopeptidase activities. HchA uses temperature-induced exposure of structured hydrophobic domains to capture and stabilize early unfolding protein intermediates under severe thermal stress.

SKP is a 17kDa trimeric periplasmic chaperone that supports outer membrane proteins in their folding and insertion into membranes. SKP protein is necessary for the normal release of ompA from the inner membrane, the maintenance of its solubility in the periplasm, and, in association with lipopolysaccharide (LPS), for the efficient folding and insertion of ompA into the outer membrane.

HSP90B1 is an abundant molecular chaperone resident endoplasmic reticulum (ER) lumenal stress protein which is part of the Hsp90 family. HSP90B1 is involved in maintaining protein homeostasis in the secretory pathway as well as functioning in the intracellular trafficking of peptides from the extracellular space to the MHC class I antigen processing pathway of antigen presentation cells. HSP90B1 has key roles in signal transduction, protein folding, protein degradation, and morphologic evolution. HSP90B1 protein associates with numerous cochaperones and involved in folding of newly synthesized proteins or stabilizing and refolding denatured proteins after stress. HSP90B1 is highly expressed in human gastric carcinoma BGC-823 cells during the whole cell cycle.

DnaJB2 is a member of the DnaJ family. The DnaJ family is one of the largest of all the chaperone families which has evolved with diverse cellular localization and functions. DnaJB2 are important mediators of proteolysis which are involved in the regulation of protein degradation, exocytosis and endocytosis. The DnaJ proteins play a significant role in the HSP70 chaperone machine by interacting with HSP70 to stimulate ATP hydrolysis. DnaJB2 is expressed almost solely in the brain, with the highest levels in the frontal cortex and hippocampus.

GroEL, HSP60 is a chaperonin located in the mitochondria which is responsible for the transportation & refolding of proteins from the cytoplasm directly into the mitochondrial matrix. GroEL is regulated by the HSP10 cochaperonin, which is a single heptameric protein ring having a molecular mass of 10 kDa which form a unique complex with HSP60. HSP10, GroES coordinates the ATPase activity of the HSP60 subunits in order to allow the release of bound polypeptide in a manner that is productive for its correct folding.

DnaK, originally identified for its DNA replication by bacteriophage l in E. coli is the bacterial HSP70 chaperone. This protein is involved in the folding and assembly of newly synthesized polypeptide chains and in preventing the aggregation of stress-denatured proteins.

HSPA9 is part of the heat shock protein 70 family which contains both heat-inducible and constitutively expressed members that are also called heat-shock cognate proteins. HSPA9 encodes a heat-shock cognate protein that is involved in the control of cell proliferation and acts as a chaperone. HSPA9 was restricted to chromosome 5, band q31, a region that is often deleted in myeloid leukemias and myelodysplasia (MDS), making it a candidate tumor suppressor gene, which is consistent with the biological function of its murine homologue. HSPA9 supresses nuclear translocation, transcriptional activation, and control of centrosome-duplication functions of p53.

The heat-shock response is elicited by exposure of cells to thermal and chemical stress and through the activation of HSFs (heat shock factors) results in the elevated expression of heat-shock induced genes. Heat shock factor binding protein-1 (HSBP1), is a 76-amino-acid protein that binds to heat shock factor 1(HSF1), which is a transcription factor involved in the HS response. During HS response, HSF1 undergoes conformational transition from an inert non-DNA-binding monomer to active functional trimers. HSBP1 is nuclear-localized and interacts with the active trimeric state of HSF1 to negatively regulate HSF1 DNA-binding activity. Overexpression of HSBP1 in mammalian cells represses the transactivation activity of HSF1. When overexpressed in C.elegans HSBP1 has severe effects on survival of the animals after thermal and chemical stress consistent with a role of HSBP1 as a negative regulator of heat shock response.

AHA1 is a cochaperone that stimulates hsp90 ATPase activity. AHSA1 binds the middle domain of Hsp90 (amino acid 272-627) and functions as an ATPase-activating protein that competes with p23 and other co-chaperones for Hsp90 binding.
AHA1 affects a step in the endoplasmic reticulum to golgi trafficking.

Heat Shock Factor Binding Protein 1-Like 1 (HSBP1L1) is a part of a family of eukaryotic proteins known as nucleotide exchange factors for HSP 70. HSBP1L1 is a protein coding gene whose expression is regulated mainly at the transcription level.

SERPINH1 is part of the serpin superfamily of serine proteinase inhibitors. SEPINH1 expression is induced by heat shock. HSP47 localizes to the endoplasmic reticulum lumen and binds collagen therefore it is a molecular chaperone which takes part in the maturation of collagen molecules, facilitating the folding and assembly of procollagen molecules, retaining unfolded molecules within the ER, and assisting the transport of correctly folded-molecules from the ER to Golgi apparatus. Autoantibodies to HSP47 protein have been found in rheumatoid arthritis. SERPINH1 binds specifically to collagen and acts as a chaperone in the biosynthetic pathway of collagen.

GroEL, HSP60 is a chaperonin located in the mitochondria which is responsible for the transportation & refolding of proteins from the cytoplasm directly into the mitochondrial matrix. GroEL is regulated by the HSP10 cochaperonin, which is a single heptameric protein ring having a molecular mass of 10 kDa which form a unique complex with HSP60. HSP10, GroES coordinates the ATPase activity of the HSP60 subunits in order to allow the release of bound polypeptide in a manner that is productive for its correct folding.

HSP27 (also known as the Estrogen-Regulated 24K protein, and hsp 28) is a member of the mammalian small heat shock protein family. Hsp27 is expressed constitutively in many tissues and its expression is increased to high levels after various types of stress including elevated temperatures, toxic metals, drugs and oxidants. Also, Hsp27 is phosphorylated in vivo on three phosphorylation sites (Ser15, Ser78 and Ser82) by protein kinases including MAPKAP kinase 2 and the stress-activated protein kinase SAPK2 (p38).

GroES protein is the co-chaperonin of GroES in E.coli and assists protein folding. GroEL mediated folding requires the co-chaperonin GroES which is essential for viability. GroES is composed of a single heptameric ring of 10kDa subunits that binds to the ends of the GroEL cylinder. GroES gene was amplified by PCR from E.coli and cloned into an expression vector. This protein was overexpressed in E.coli and was purified by using conventional chromatography techniques.

Heat Shock Protein B9 (HSPB9) is a member of the small heat shock protein (HSP20) family. HSPB9 is found in the cytoplasm as well as in the nucleus. HSPB9 is expressed specifically in the testis.

HSP10 is part of the molecular chaperons, that are crucial for thir efficient folding of proteins in normal as well as stress conditions. GroES function is to bind to HSP60 in the presence of ATP, thus causing a change in the HSP60 conformation & enclosing the protein substrate within the complex. ATP hydrolysis by chaperonin-60 which destabilizes the HSP10-HSP60 complex, thereby allowing it to dissociate and secrete the substrate protein. GroES having the NCBI accession number of NP_002148 was purified by using conventional chromatography techniques.

Once Chinese hamster K12 cells are starved from glucose, the synthesis of GRP (glucose-regulated protein) expressed. HSPA5 also called BiP, is part of the HSP70 family and plays a role in the folding and assembly of proteins in the endoplasmic reticulum. HSPA5 plays a key role in monitoring protein transport through the cell.
HSPA5 is a stress response protein which is induced by agents or conditions that adversely affect endoplasmic reticulum function. HSPA5 is crucial for the proper glycosylation, folding as well as for the maintenance of cell homeostasis and the prevention of apoptosis. HSPA5 is differentially expressed in the dorsolateral prefrontal cortex from patients with schizophrenia. HSPA5 guides posttranslational hepatitis B virus large envelope protein import into the mammalian ER. HSPA5 actively regulates multiple malignant phenotypes, including cell growth, migration, and invasion.

The HSP70 family is found in many intracellular compartments such as chloroplasts, endoplasmic reticulum, mitochondria, and cytosol. These proteins are induced by a variation of biological stresses, including heat stress, in every organism. HSP70 has a range of functions. For example: HSP70 acts as molecular chaperones facilitating the assembly of multi-protein complexes, HSP70 take part in the translocation of polypeptides across cell membranes and to the nucleus, and HSP70 assists in the proper folding of nascent polypeptide chains.
HSP70 is a mitochondrial import equipment and has a crucial part in the cytosolic endoplasmic reticulum. Lately, extracellular localized HSP was discovered to take an important part in the induction of a cellular immune response.

HSP104 is a molecular chaperone required for stress tolerance and for maintenance of [psi(+)] prions in the budding yeast Saccharomyces cerevisiae. Hsp104 can protect yeast cells against high temperature and high concentration of ethanol but mutation studies have shown this protein is not required for normal growth. Hsp104 was cloned into an E. coli expression vector and was purified to apparent homogeneity by using conventional column chromatography techniques.

Dsb proteins are in charge for the formation and rearrangement of disulfide bonds during the folding of secreted and membrane proteins in bacteria. DsbG has disulfide bond isomerase and chaperone activity. DsbG interacts with refolding intermediates of chemically denatured citrate synthase and prevents their aggregation in vitro. DsbG shares sequnce homology with DsbC. DsbG forms a stable periplasmic dimer and displays an equilibrium constant with glutathione comparable with DsbA and DsbC. DsbG is expressed at roughly 25% level of DsbC.

GroEL protein is the major heat shock protein of E.coli and belongs to the chaperonin (HSP60) family. GroEL protein prevents misfolding of proteins and promotes the refolding and proper assembly of unfolded polypeptiedes generated under stress condition.

HSPH1 analysis is used as an indicator and as a diagnostic aid in problematic lesions.
HSPH1 chaperones the responses to endoplasmic reticulum (ER) stress during its interactions with GRP78 and GSK3, and without HSP105 cell death following ER stress proceeds by a non-caspase-3-dependent process.
HSPH1 is highly expressed in a variety of human tumors.
HSPH1 is a mammalian member of the HSP105/110 family, a diverged subgroup of the HSP70 family. HSP105 has 2 isoforms, alpha and beta. Hsp105a associates with Hsp70/Hsc70 as complexes in vivo and regulates the chaperone activity of Hsp70/Hsc70 negatively in vitro and in vivo.

HSPBAP1 holds a jumonji C (JMJC) domain. HSPBAP1 protein has a part in regulating stress response in the living cell. HSPBAP1 is known to interact with CRYAB and HSPB1.