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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.

MECP2 is the key modificator of eukaryotic genomes and has a crucial part in mammalian development.
Human proteins MECP2, MBD1, MBD2, MBD3, and MBD4 form a family of nuclear proteins linked by the existence in each of a methyl-CpG binding domain (MBD). Each one of these proteins, with the exception of MBD3, can bind specifically to methylated DNA. In addition, MECP2, MBD1 and MBD2 can inhibit transcription from methylated gene promoters. Unlike other MBD family members, MECP2 is X-linked and subject to X inactivation. MECP2 is expendable in stem cells, but is vital for embryonic development. MECP2 gene mutations are the cause of most cases of Rett syndrome, a progressive neurologic developmental disorder and one of the most common reasons of mental retardation in females.

Zinc-alpha-2-glycoprotein (ZAG) is found in body fluids such as serum, sweat, and seminal and breast cyst fluids. It is identical in amino acid sequence to tumor-derived lipid mobilizing factor (LMF), a protein associated with the dramatic loss of adipose body stores in cancer cachexia, and has been shown to stimulate lipolysis by adipocytes in vivo and in vitro. A role for ZAG has been proposed in the regulation of body weight, and age-dependent changes in genetically influenced obesity, and also it regulates melanin production by normal and malignant melanocytes. It has also recently been classified as a novel adipokine in that it is produced by both white and brown fat adipocytes and may act in a local autocrine fashion in the reduction of adiposity in cachexia. Controlling ZAG/LMF's activity could be life-saving in the management of certain cancers and other cachexiainducing conditions, and its possible normal role in body fat store homeostasis is deserving of understanding in its own right. ZAG exhibits a class I major histocompatibility complex (MHC) fold but is a soluble protein rather than being anchored to plasma membranes and does not associate with alpha-2-microglobulin in humans. Like antigen-presenting MHC class I proteins, ZAG has an open apical groove, and X-ray crystallography of human derived ZAG revealed an unidentifiable electron density in a similar position to that occupied by antigenic peptides in classical MHC proteins and glycolipids in isoforms of CD1. This presumptive ligand is not a peptide, and the groove is too small to hold a glycolipid such as is presented by CD1 isoforms. By analogy with all other MHC class I-related proteins that have an open apical groove [some do not ], occupancy by a ligand is probably crucial to ZAG's biological function. Despite all of the structural and biochemical evidence that ZAG binds a ligand, none has so far been found by extraction from protein isolated from biological fluids. This difficulty could be because the ligand is labile, heterogeneous, or readily lost during purification procedures. Knowing more about how ZAG interacts with the compounds it has been found to bind, both natural and artificial, will inform searches for the elusive ligand(s) and its/their role in ZAG's signaling function.

Apolipoprotein-D is mainly associated with high density lipoproteins in human plasma. Apolipoprotein-D is an atypical apolipoprotein and, based on its primary structure, Apolipoprotein-D is a member of the lipocalin family. Lipocalins adopt a beta-barrel tertiary structure and transport small hydrophobic ligands. Apolipoprotein-D binds cholesterol, progesterone, pregnenolone, bilirubin and arachidonic acid.
Apolipoprotein-D is expressed in numerous tissues having high levels of expression in spleen, testes and brain. Apolipoprotein-D is present at high concentrations in the cyst fluid of women with gross cystic disease of the breast, a condition associated with increased risk of breast cancer. Apolipoprotein-D accumulates in regenerating peripheral nerves and in the cerebrospinal fluid of patients with neurodegenerative conditions, such as Alzheimer's disease. Apolipoprotein-D participates in maintenance and repair within the central and peripheral nervous systems. Apolipoprotein-D is a multi-ligand, multi-functional transporter and transports a ligand from 1 cell to another within an organ, scavenge a ligand within an organ for transport to the blood or could transport a ligand from the circulation to specific cells within a tissue.

Energy Homeostasis Associated (ENHO) participates in glucose homeostasis maintenance and lipid metabolism. ENHO is expressed in the liver and the brain. The role of ENHO in obesity or diabetes is studied.

BID is a pro-apoptotic Bcl-2 protein having only the BH3 domain. In reaction to apoptotic signaling, BID interacts with another Bcl-2 family of cell death regulators, called Bax, they form a heterodimer resulting to the insertion of Bax into the outer mitochondrial membrane. Bax induces the opening of the mitochondrial voltage-dependent anion channel which lead to the release of cytochrome c and other pro-apoptotic factors from the mitochondria resulting in activation of caspases. BID is a mediator of mitochondrial damage induced by caspase-8 (CASP8). CASP8 cleaves BID, and the COOH-terminal part translocates to mitochondria where it triggers cytochrome c release. The major proteolytic product p15 BID releasea cytochrome c. Isoform 1, Isoform 2 and Isoform 4 induce ice-like proteases and apoptosis while Isoform 3 does not induce apoptosis.

The B19 virus, usually referred to as parvovirus B19 or sometimes as erythrovirus B19, belongs to the family of parvoviruses, genus erythrovirus. B19 virus causes a childhood rash named “fifth disease” or “erythema infectiosum” which is ordinarily known as “slapped cheek syndrome”. Erythroviruses are members of the Parvoviridae family of small DNA viruses. The B19 virus is a non-enveloped, icosahedral virus which contains a single-stranded linear DNA genome. Parvovirus B19 is classified as erythrovirus because of its capability to invade red blood cell precursors in the bone marrow. This virus is mainly spread by infected respiratory droplets; though, blood-borne transmission has also been reported.

The B19 virus, usually referred to as parvovirus B19 or sometimes as erythrovirus B19, belongs to the family of parvoviruses, genus erythrovirus. B19 virus causes a childhood rash named “fifth disease” or “erythema infectiosum” which is ordinarily known as “slapped cheek syndrome”. Erythroviruses are members of the Parvoviridae family of small DNA viruses. The B19 virus is a non-enveloped, icosahedral virus which contains a single-stranded linear DNA genome. Parvovirus B19 is classified as erythrovirus because of its capability to invade red blood cell precursors in the bone marrow. This virus is mainly spread by infected respiratory droplets; though, blood-borne transmission has also been reported.

Peptidase Inhibitor 3, also referred to PI3, is neutrophil and pancreatic elastase-specific inhibitor of skin. The protein may prevent elastase mediated tissue proteolysis. PI3 has shown inhibition of alpha-4-beta-2/CHRNA2-CHRNB2 nicotinic acetylcholine receptor, a weak inhibition on Kv11.1/KCNH2/ERG1 and on the transient receptor potential cation channel subfamily V member 1.

Carcinoembryonic Antigen-Related Cell Adhesion Molecule 3, also known as CEACAM3, is a member of the immunoglobulin super family. The genes in this family encode cell adhesion proteins, which are expressed at higher levels in tumorous tissues rather than in normal tissues. CEACAM3 plays a significant part in the clearance of pathogens through the innate immune system. In addition, CEACAM3 is accountable for RAC1 stimulation in the course of pathogen phagocytosis.

Adenosine deaminase CECR1 isoform (CECR1) belongs to a family of adenosine deaminase-related growth factors. Adenosine deaminase is a key enzyme of purine nucleotide metabolism. CECR1 is a secreted protein, which is expressed in various tissues, with the highest expression in the lymphoblasts, heart, lung, and the placenta.

PTX3 is part of the pentraxin family sharing the C-terminal domain with short pentraxins and containing a unique N-terminal domain. PTX3 is produced and released at inflammatory sites by various cell types including monocytes/macrophages, endothelial cells, vascular smooth muscle cells, fibroblasts, and adipocytes. PTX3 is involved in the regulation of innate resistance to pathogens, inflammatory reactions, possibly clearance of self-components and female fertility. PTX3 is used as a marker for disease activity of psoriasis. High serum PTX3 levels are associated with the disease severity of systemic sclerosis. Elevated serum PTX3 is associated with pulmonary fungal infections.

Leukocyte Cell-Derived Chemotaxin 2 (LECT2) functions as a chemotactic factor to neutrophils. LECT2 stimulates the proliferation of chondrocytes and osteoblasts. LECT2 is strongly expressed in the liver and weakly in the testis. LECT2 is a secreted, 16kDa protein which serves as a chemotactic factor to neutrophils and stimulates the growth of chondrocytes and osteoblasts. LECT2 protein has a high sequence similarity to the chondromodulin repeat regions of the chicken myb-induced myeloid 1 protein. A polymorphism in the LECT2 gene is linked with rheumatoid arthritis.

Sclerostin Domain Containing 1 (SOSTDC1) belongs to the sclerostin family and an N-glycosylated, secreted protein with a C-terminal cystine knot-like domain. The SOSTDC1 protein acts as a bone morphogenetic protein (BMP) antagonist. Specifically, SOSTDC1 directly associates with BMPs, prohibiting them from binding their receptors, thus regulating BMP signaling throughout cellular proliferation, differentiation, and programmed cell death. SOSTDC1 may also be involved in the onset of endometrial receptivity for implantation/sensitization for the decidual cell reaction Enhances Wnt signaling and hinders TGF-beta signaling. In addition, SOSTDC1 directly antagonizes the activity of BMP2, BMP4, BMP6 and BMP7 in a dose-dependent manner.

BCA-1 is a CXC chemokine that is highly expressed in thesecondary lymphoid organs, such as follicles of the spleen, lymph nodes, and Peyer's patches. CXCL13 promotes the migration of B lymphocytes (compared to T cells and macrophages), by stimulating calcium influx into, and chemotaxis of, cells expressing Burkitt's lymphoma receptor 1 (BLR1). BCA1 therefore function in the homing of B lymphocytes to follicles. Human BCA-1 shares a 64% amino acid sequence similarity with the mouse protein and 23 - 34% amino acid sequence identity with other known CXC chemokines. Recombinant or chemically synthesized BCA1 is a potent chemoattractant for B lymphocytes but not T lymphocytes, monocytes or neutrophils. BLR1, a G protein-coupled receptor originally isolated from Burkitt’s lymphoma cells, has now been shown to be the specific receptor for BCA1. Among cells of the hematopoietic lineages, the expression of BLR-1, now designated CXCR-5, is restricted to B lymphocytes and a subpopulation of T helper memory cells.

Elcatonin is a Calcitonin derivative which is transformed from eel´s calcitonin by changing the S-S bond into the stable C-N bond. It inhibits the absorption and autolysis of bones, thus leads to blood calcium descending. In addition, it inhibits the bone salts dissolving and transferring and promotes the excretion of calcium and phosphorus in urine. Meanwhile, it inhibits renal tubules reabsorbing calcium, phosphorus and sodium and keeps blood calcium at normal level. It is mainly used for remitting or eliminating the pain caused by Osteoporosis.

EPGN is an EGF-related polypeptide growth factor that signals through the ErbB receptor-1. EPGN is produced in numerous tissues, including the testis, liver, heart and in certain tumor cells. EPGN is mitogenic for fibroblasts and epithelial cells. Human EPGN is originally synthesized as a glycosylated 14.7 kDa transmembrane precursor protein, which is processed by proteolytic cleavage to produce a mature soluble sequence.

The 23kDa two-domain periplasmic chaperone FIMC from E.coli is vital for the assembly of type-1 pili, which are filamentous, very oligomeric protein complexes anchored to the outer bacterial membrane that mediate adhesion of pathogenic E. coli strains to host cell surfaces and persist in macrophages.

RELM-beta (Resistin-Like Molecule-beta) is a member of a recently identified family of secreted proteins containing a conserved cystein-rich C-terminus. The RELM family consists of resistin (also called FIZZ3), RELM-alfa (FIZZ1), RELM-beta (FIZZ2) and RELM-gamma. Only resisistin and RELM-beta were found in humans whereas all four RELM family members were identified in rodents.
RELM-beta appears to be produced as a homodimer exclusively by intestinal goblet cells and can be found in high quantities in stool. Remarkably, stool of germ-free mice displaying sterile intestinal tract does not contain RELM-beta until bacterial colonization takes place after pathogen-free mice entered natural environment. Some, but not all, colon carcinoma cell lines secrete RELM-beta into the cell culture supernatant.
The physiological function of RELM-beta is not known. High doses of recombinant RELM-beta showed hyperglycemic effects including lowered glucose disposal and increased hepatic glucose production in mice.

Crystallins are the main structural proteins of the vertebrate eye lens, where they maintain the transparency and refractive index of the lens. Crystallins are divided into 3 fprotein families, α, β, & γ families. Because lens central fiber cells lose their nuclei during development, these crystallins are prepared and then retained throughout life, making them extremely stable proteins. CRYBB1 is a beta basic group member and undergoes extensive cleavage at its N-terminal extension during lens maturation.

IFIH1 is a DEAD box protein which is upregulated in response to treatment with beta-interferon and a protein kinase C-activating compound, mezerein. Irreversible reprogramming of melanomas can be attained by therapy with both these agents; treatment with either agent alone only achieves reversible differentiation. DEAD box proteins are implicated in several cellular processes involving alteration of RNA secondary structure such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly.

Endoglin is a type I membrane glycoprotein located on cell surfaces and is part of the TGF beta receptor complex.
The Endoglin protein consists of a homodimer of 180 kDA with disulfide links. Endoglin has been found on endothelial cells, activated macrophages, fibroblasts, and smooth muscle cells. Furthermore, Endoglin has been found to be part of the TGF-beta1 receptor complex. Endoglin thus may be involved in the binding of TGF-beta1, TGF-beta3, activin-A, BMP-2, and BMP-7. Beside TGF-beta signaling endoglin may have other functions. It has been postulated that endoglin is involved in the cytoskeletal organization affecting cell morphology and migration. Endoglin has a role in the development of the cardiovascular system and in vascular remodeling. Endoglin expression is regulated during heart development . Experimental mice without the endoglin gene die due to cardiovascular abnormalities.

TAR DNA Binding Protein (TARDBP) was initially recognized as a transcriptional repressor which binds to chromosomally integrated TAR DNA and represses HIV-1 transcription. In addition, TARDBP has been detected in individuals diagnosed with chronic traumatic encephalopathy as well, which is a condition that often imitates ALS andhas been related with athletes who have experienced multiple concussions and other types of head injury.TARDBP has been shown to bind both DNA and RNA, it has multiple functions in transcriptional repression, pre-mRNAsplicing and translational regulation.