Heat Shock Protein

GrpE , co-chaperone of E.coli, participates actively in the response to hyperosomotic and heat shock by preventing the aggregation of stress-denatured proteins in association with DnaK. This protein is the nucleotide exchange factor for DnaK and may function as a thermosensor. Several rounds of ATP-dependent interactions between DnaJ, DnaK and GrpE are required for fully efficient folding.

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.

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.

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.

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.

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.

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.

STUB1, is a cytoplasmic protein whose amino acid sequence is highly preserved across species. STUB1 interacts with the molecular chaperones Hsc70-Hsp70 and Hsp90 through its TPR domain, whereas its U-box domain contains its E3 ubiquitin ligase activity. STUB1 interaction with these molecular chaperones lead to in client substrate ubiquitylation and degradation by the proteasome. therefore, STUB1 acts to tilt the folding-refolding mechanism towards the degradative pathway, and it serves as a link between the two. STUB1 inhibits anchorage-independent cell growth and metastatic potential by degrading oncogenic proteins including SRC-3. Inhibition of tyrosine kinase activity of Her-2/neu by quercetin specifies an lateration in the Her-2/neu structure which promotes STUB1 recruitments and down-regulation of Her-2/neu. STUB1 recognizes and mediates degradation of toxic, oligomeric forms of alphaSyn.

ST13 is an adaptor protein (co-chaperone) that mediates the association of HSP70 & HSP90 and appears in early receptor complexes. ST13 plays a role in the assembly process of glucocorticoid receptor, which requires the assistance of multiple molecular chaperones. The expression of ST13 is downregulated in colorectal carcinoma tissue signifying that is candidate tumor suppressor gene. Through common binding to both Hsp70 and Hsp90, ST13 functions as an adaptor that can integrate Hsp70 and Hsp90 interactions. The expression of ST13 decreases in colorectal cancer tissue compared with that in adjacent normal tissue. ST13 is mostly expressed in colorectal epithelia and adenocarcinoma cells. ST13 functions to promote the efficiency of glucocorticoid receptor maturation in cells. The expression levels of the ST13 gene were significantly decreased in primary tumors compared with adjacent mucosa.

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.

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.

DsbE is a reducing Dsb protein involved in electron transfer for cytochrome c maturation in the periplasm of Escherichia coli. DsbE is one of 12 proteins required for their assembly in the periplasm. DsbE functions is to decrease disulphide bonds formed among correctly paired cysteine residues in the cytochrome c apoproteins prior to haem attachment by CcmF and CcmH.

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.

Hsp70-binding protein 1 (HSPBP1) is a member of a family of eukaryotic proteins identified as nucleotide exchange factors for HSP 70 that exhibit varying degrees of compartment and species specificity. HSPBP1 is localized mainly in cytoplasm and nucleus but is also found extracellularly. HSPBP1 is mostly expressed in heart and skeletal muscle .HSPBP1 binds to HSP 70, inhibits its activity and promotes dissociation of nucleotides from the HSP 70 ATPase domain. In addition, HSPBP1 inhibits HSPA1A chaperone activity by changing the conformation of the ATP-binding domain of HSPA1A and obstructing the ATP binding. HSPBP1 may also have a role in tumor (dys)regulation of chaperone proteins. Furthermore, HSPBP1 hinders ubiquitination mediated by STUB1 and inhibits chaperone-assisted degradation of immature CFTR.

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.

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.

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.The protein coding region of the substrate binding domain of DnaK (amino acids 385-638) was amplified by PCR and cloned into an E. coli expression vector. The substrate binding domain of DNAK was purified to apparent homogeneity by using conventional column chromatography techniques. Additional amino acid (Met) is attached at N- terminus.

HSPB8 is part of the superfamily of small heat-shock proteins containing a conservative alpha-crystallin domain at the C-terminal part of the molecule. HSPB8 is induced by estrogen in estrogen receptor-positive breast cancer cells. HSPB8 protein functions as a chaperone in association with BAG3, a stimulator of macroautophagy. HSPB8 participates in the regulation of cell proliferation, apoptosis, and carcinogenesis. Mutations in HSPB8 gene have been related with different neuromuscular diseases, including Charcot-Marie-Tooth disease.

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. Dnak(residues 508-638) of the substrate binding domain is a-helical and appears to act as a lid covering the substrate binding cleft. DnaK(amino acid 508-638) was purified to apparent homogeneity by using conventional column chromatography techniques. Additional amino acid (Met) is attached at N- terminus.

HSPB8 displays temperature-dependent chaperone activity. HSPB8 acts as a mn(2+)-dependent serine-threonine- specific protein kinase. we are not convinced that this is its true role. Defects in HSPB8 are a cause of distal hereditary motor neuropathy type ii (DHMN2) also known as distal spinal muscular atrophy (DSMA) and spinal muscular atrophy of the charcot-marie-tooth type. it is an autosomal dominant disorder of lower motor neurons characterized by distal muscle weakness.

HSPB7 is part of the Heat shock protein beta family. The HSPB family is one of the more diverse families within the group of HSP families. Several members have chaperone-like activities and/or participate in cytoskeletal stabilization. Several members also show a dynamic, stress-induced translocation to SC35 splicing speckles. HSPB7 constitutively localized to SC35 splicing speckles, determined by its N-terminus. HSPB7 does not support refolding though HSPB1 and HSPB5 chaperone heat unfolded substrates and keet them folding competent.

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. Dnak(residues 508-638) of the substrate binding domain is a-helical and appears to act as a lid covering the substrate binding cleft. DnaK(amino acid 508-638) was purified to apparent homogeneity by using conventional column chromatography techniques. Additional amino acid (Met) is attached at N- terminus.

Heat shock prtein beta-6, also known as HSPB6 is a member of the small heat shock protein (HSP20) family. This locus encodes a heat shock protein. HSPB6 plays a role in smooth muscle relaxation. Among the diseases which are associated with HSPB6: Cerebral hemorrhage and Cerebral amyloid angiopathy.

HSP70 is a human heat shock protein. HSP-70 is an important part of the cell's machinery for protein folding, and help to protect cells from stress. In most species, there are many proteins that belong to the HSP70 family. Some of these are only expressed under stress conditions, while some are present in cells under normal growth conditions and are not heat-inducible. They can be found in different cellular compartments (nuclear, cytosolic, mitochondrial, endoplasmic reticulum, etc...).

HSPB3 is a muscle-specific small heat shock protein which is expressed specially in heart and skeletal muscle. Mammalian small heat shock proteins (sHSP) are highly expressed proteins with varied roles, including the assembly and impounding of multi-protein complexes, transportation of nascent polypeptide chains thru cellular membranes and regulation of protein folding. HSPB3 perform as an ATP-dependent chaperone protein which takes part in the refolding of denatured proteins and inhibition of actin polymerization.

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.

Heat shock protein beta-2 (HSPB2) is a member of the small heat shock protein (HSP20) family. HSPB2 is a regulator of DMPK kinase.

DnaK, originally identified for its DNA replication by bacteriophage l in E. coli is the bacterial HSP-70 chaperone. This protein is involved in the folding and assembly of newly synthesized polypeptide chains and in preventing the aggregation of stress-denatured proteins.
DnaK(amino acids1-384) is N-terminal ATPase domain and ATP bound to the ATPase domain induces a conformational change in the substrate binding domain (residues 385-638). The protein coding region of the ATPase domain of DNAK (amino acids 1-384) was amplified by PCR and cloned into an E. coli expression vector. The ATPase domain of DNAK was purified to apparent homogeneity by using conventional column chromatography techniques.

HSPB11 is a component of IFT complex B composed of IFT88, IFT57, TRAF3IP1, IFT52, IFT27, HSPB11 and IFT20. HSPB11 is detected in the placenta.

DnaJ (Hsp40) Homolog, Subfamily C, Member 27 (DNAJC27) which contains one J domain is a part of the small GTPase superfamily. DNAJC27 is a GTPase which activates the MEK/ERK pathway and induces cell transformation when overexpressed.

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.

DnaJ homolog subfamily C member 24 (DNAJC24) belongs to the ZCSL family of proteins and each contain one DPH-type zinc finger. DNAJC24 is involved in the synthesis of diphthamide, a protein found on translation elongation factor EF-2 which is the target of bacterial ADP-ribosylating toxins. DNAJC24 stimulates the ATPase activity of few Hsp70-type chaperones. DNAJC24 detected in heart, brain, spleen, lung, liver, kidney and testis.

HSPA8 is part of the heat shock protein 70 family which includes both heat-inducible and constitutively expressed proteins (heat-shock cognate proteins). HSPA8 is a heat-shock cognate protein that binds to nascent polypeptides to facilitate correct folding. HSPA8 plays a role as an ATPase in the disassembly of clathrin-coated vesicles through transport of membrane components through the cell. HSPA8 is expressed in colon cancer cells, HSPA8 takes part in reovirus outer capsid disassembly, through membrane penetration, to plan the entering particle for gene expression and replication. serum HSPA8 concentrations are reduced in normal human pregnancy. HSPA8 plays a role in androgen action on dermal papilla cells. HSPA8 is directly linked with Influenza virus matrix protein 1 and thus required for viral production.

DNAJC19 is part of a complex involved in the ATP-dependent transport of transit peptide-containing proteins from the inner cell membrane to the mitochondrial matrix. DNAJC19 is a single-pass membrane protein which contains a J domain and is localized to the inner membrane of the mitochondrion. Expressed ubiquitously, DNAJC19 acts as a component of the mitochondrial DNAJC19 complex that is responsible for the ATP-dependent translocation of select proteins from the inner mitochondrial membrane to the mitochondrial matrix. Defects in the DNAJC19 gene are the cause of 3-methylglutaconic aciduria type 5 (MGA5), otherwise known as dilated cardiomyopathy with ataxia (DCMA).

HSPA6 is a distinctive member of the human Hsp70 chaperone that takes part in cellular processes such as protein trafficking, folding, and prevention of aggregation. HSPA6 is strictly stress-inducible, having little or no basal expression levels in most cells. HSPA6 and HSP72 are are involved in cell survival of proteotoxic stress.

DNAJC15 which is expressed ubiquitously and located on the membrane contains 1 J domain. In many advanced cases of ovarian adenocarcinoma DNAJC15 is absent or down-regulated, due to hypermethylation and allelic loss. Loss of expression correlates with increased resistance to antineoplastic drugs, such as cisplatin. DNAJC15is a crucial component of the TIM23 translocase complex and stimulates the ATPase activity of HSPA9.

Binding immunoglobulin protein (BiP or HSPA5) is a member of the family of ~70kDa heat shock proteins (HSP 70). HSPA5 is a stress response protein which is induced by agents or conditions that adversely affect endoplasmic reticulum (ER) function. HSPA5 is crucial for the proper glycosylation, folding as well as for the maintenance of cell homeostasis and the prevention of apoptosis.

DnaJ (Hsp40) Homolog, Subfamily C, Member 12 (DNAJC12) belongs to the DnaJ/Hsp40 family. DnaJ/Hsp40 family members are linked with complex assembly, protein folding, and export. DnaJ/Hsp40 proteins are extremely conserved throughout evolution and function as co-chaperones regulating protein folding, transport, translational initiation and gene expression. DnaJC12 has a role in protein folding and export and is believed to be involved in estrogen control and the development of breast cancer. DNAJC12 is expressed at high levels in the brain, heart, and testis, and at reduced levels in the kidney and stomach.

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.

DnaJ homolog subfamily B member 8 (DNAJB8) is superior suppressors of aggregation and toxicity of disease-associated polyglutamine proteins.DNAJB8 is a member of the DNAJ/HSP40 family of proteins that regulate chaperone activity. DNAJB8 is (de)acetylated at 2 conserved C-terminal lysines which aren’t involved in substrate binding, but do have a role in suppressing protein aggregation. DNAJB8 has been implicated as a cancer-testis antigen and as a cancer stem-like cell antigen involved in renal cell carcinoma.

DnaJ homolog subfamily B member 6 (DNAJB6) belongs to the DNAJ protein family. The DNAJ family members are characterized by a highly conserved amino acid stretch known as the 'J-domain' and function as one of the two major classes of molecular chaperones involved in a wide range of cellular events, such as protein folding and oligomeric protein complex assembly. DNAJB6 may also play a role in polyglutamine aggregation in specific neurons.

Binding immunoglobulin protein (BiP or HSPA5) is a member of the family of ~70kDa heat shock proteins (HSP 70). HSPA5 is a stress response protein which is induced by agents or conditions that adversely affect endoplasmic reticulum (ER) function. HSPA5 is crucial for the proper glycosylation, folding as well as for the maintenance of cell homeostasis and the prevention of apoptosis.

DnaJ (Hsp40) Homolog, Subfamily B, Member 4 (DNAJB4) is a member of the evolutionarily conserved DNAJ/HSP40 protein family. DNAJB4 subunit configuration is homodimer. DNAJB4 possibly functions as a chaperone. DNAJB4 C-terminal section interacts with the C-terminal tail of OPRM1. DNAJB4 also has an interaction with SDIM1. DNAJB4 is expressed in the heart, pancreas and skeletal muscle, and to a lesser extent in the brain, placenta and liver.

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.

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.

DNAJB11 is a member of the evolutionarily conserved DNAJ/HSP40 family of proteins, which regulate molecular chaperone activity by stimulating ATPase activity. DNAJB11 serves as a co-chaperone for HSPA5 and binds directly to both unfolded proteins which are substrates for ERAD and nascent unfolded peptide chains, but dissociates from the HSPA5-unfolded protein complex before folding is completed.

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.

Human HSP40 (heat shock protein with molecular size of 40kDa) is one of the mammalian homologues of bacterial DnaJ heat shock protein and regulates cellular processes by aiding in the folding, transport and assembly. HSP40 protein contains the J-domain which controls interaction with the ATPase domain of DnaK.

HSPA13 belongs to the heat shock protein 70 family and is related to microsomes. Members of this protein family take part in the processing of cytosolic and secretory proteins, in addition to the exclusion of denatured or incorrectly-folded proteins. HSPA13 is known to cooperate with PLIC-1 and PLIC-2, proteins which have a role in the signaling connection between the membrane receptors for thrombospondin and the cytoskeleton.

DnaJ, Heat shock protein, functions in association with DnaK(Hsp70) molecular chaperone to facilitate protein folding. p70 chaperone. DnaJ plays a key role in the chaperone reaction by stimulating the ATPase activity and activating the substrate binding of Hsp70. DnaJ consists of four domains that are N-terminal 76 amino acid J-domain, G/F domain, zinc-binding cystein rich CR-domain, C-terminal CTD-domain and they are conserved to various degrees among the homologues.