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The 14-3-3 family of proteins plays a key regulatory role in signal transduction, checkpoint control, apoptotic and nutrient-sensing pathways. 14-3-3 proteins are highly conserved and ubiquitously expressed. There are at least seven isoforms that have been identified in mammals. The 14-3-3gamma, a subtype of the 14-3-3 family of proteins, was thought to be brain and neuron-specific. It has been shown to interact with RAF1 and protein kinase C, proteins involved in various signal transduction pathways.

GH-releasing peptides (GHRPs) are synthetic peptides that like GHRH act directly on pituitary somatotrophs to stimulate GH release. GHRP-2, an investigational drug, is one of the most potent members of the GHRP family. It has been shown to be effective in adults via the oral and intranasal as well as the iv route of administration.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C, with molecular weight of 13260 Da, is composed of 120 amino acids, lacks carbohydrate and has two disulfide bridges located near the carboxyl terminus. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and, subsequently, the atherosclerosis and abdominal aortic aneurysm.

Cystatin 5 (CST5) is a novel member of the cystatin superfamily, which encompasses proteins that contain multiple cystatin-like sequences. Some members are active cysteine protease inhibitors, while others have lost or possibly never had this inhibitory activity. The superfamily is comprised of 3 inhibitory families: the type 1 cystatins (stefins), type 2 cystatins and the kininogens. Type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in various human fluids and secretions.

Activins are homodimers or heterodimers of the different β subunit isoforms, part of the TGFβ family. Mature Activin A has two 116 amino acids residues βA subunits (βA-βA). Activin displays an extensive variety of biological activities, including mesoderm induction, neural cell differentiation, bone remodelling, haematopoiesis, and reproductive physiology. Activins takes part in the production and regulation of hormones such as FSH, LH, GnRH and ACTH. Cells that are identified to express Activin A include fibroblasts, endothelial cells, hepatocytes, vascular smooth muscle cells, macrophages, keratinocytes, osteoclasts, bone marrow monocytes, prostatic epithelium, neurons, chondrocytes, osteoblasts, Leydig cells, Sertoli cells, and ovarian granulosa cells.

ADAM10 is part of the ADAM family which are cell surface proteins with a distinctive structure possessing both potential adhesion and protease domains. ADAM10 cleaves many proteins including TNF-alpha and E-cadherin. ADAM10 cleaves the membrane-bound precursor of tnf-alpha at 76- ala-|-val-77 to its mature soluble form. ADAM10 is in charge for the proteolytic release of several other cell-surface proteins, including ephrin-a2 and for constitutive and regulated alpha-secretase cleavage of amyloid precursor protein. ADAM10 is involved in the normal cleavage of the cellular prion protein. ADAM10 is involved in the cleavage of the adhesion molecule l1 at the cell surface and in the release of membrane vesicles, suggesting a vesicle-based protease activity. ADAM10 controls the proteolytic processing of notch and mediates lateral inhibition during neurogenesis.

Proteasomal ubiquitin receptor ADRM1 (ADRM1) functions as a proteasomal ubiquitin receptor. ADRM1 is an integral plasma membrane protein which promotes cell adhesion. ADRM1 is assumed to undergo O-linked glycosylation. ADRM1 employs the deubiquitinating enzyme UCHL5 at the 26S proteasome and promotes its activity.

PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerate the folding of proteins. Cyclophilin-A is a cyclosporin binding-protein and may play a role in cyclosporin A-mediated immunosuppression. Cyclophilin-A can also interact with several HIV proteins, including p55 gag, Vpr, and capsid protein, and has been shown to be necessary for the formation of infectious HIV virions. Multiple pseudogenes that map to different chromosomes have been reported.

Metadherin (MTDH) downregulates SLC1A2/EAAT2 promoter activity when expressed ectopically. MTDH activates the nuclear factor kappa-B (NF-kappa-B) transcription factor. Furthermore, MTDH promotes anchorage-independent growth of immortalized melanocytes and astrocytes which is a central component in tumor cell expansion. In addition, MTDH promotes lung metastasis and also has an effect on bone and brain metastasis, possibly by enhancing the seeding of tumor cells to the target organ endothelium. Metadherin also induces chemoresistance.

Akt1, also known as Akt or else protein kinase B (PKB) is an important molecule in mammaliancellular signaling. In humans, there are three genes in the "Akt family": Akt1, Akt2, and Akt3. Moreover, these enzymes are members of the serine/threonine-specific protein kinase family (EC2.7.11.1). Akt1 is involved in cellular survival pathways, by inhibiting apoptoticprocesses. Akt1 is also able to induce protein synthesis pathways, and is therefore a key signaling protein in the cellular pathways which lead to skeletal muscle hypertrophy, and general tissue growth. Since it can block apoptosis, and thereby promote cell survival, Akt1 has been implicated as a most important factor in numerous types of cancer. Akt (now also called Akt1) was at first identified as the oncogenein the transforming retrovirus, AKT8.

Nectin Cell Adhesion Molecule 2, also known as NECTIN2, is a Ca(2+)-independent cell-cell adhesion molecule which is one of the plasma membrane components of adherens junctions. NECTIN2 takes a vital part in the establishment of homotypic as well as heterotypic cell to cell contacts. NECTIN2 is essential for resisting herpes simplex virus type 2 infection in transfected cells. NECTIN2 is also a possible target for antibody therapy of breast & ovarian cancers. NECTIN2 might be related with human longevity. Two diseases which have been associated with NECTIN2 are Herpes Simplex and Ovarian Cystic Teratoma.

Neuroglobin, 151 amino acid residue protein, mainly expressed in vertebrate brain and retina, is a recently identified member of the globin superfamily. Augmenting O (2) supply, neuroglobin promotes survival of neurons upon hypoxic injury, potentially limiting brain damage. Moreover, neuroglobin may be a novel oxidative stress-responsive sensor for signal transduction in the brain. Neuroglobin expression is increased by neuronal hypoxia in vitro and focal cerebral ischemia in vivo, and neuronal survival after hypoxia is reduced by inhibiting neuroglobin expression with an antisense oligodeoxynucleotide and enhanced by neuroglobin overexpression.

RANKL binds to tnfrsf11b/opg and to tnfrsf11a/rank. Osteoclast differentiation and activation factor. augments the ability of dendritic cells to stimulate naive t-cell proliferation. May be an important regulator of interactions between t-cells and dendritic cells and may play a role in the regulation of the t-cell-dependent immune response. sRANKL may also play an important role in enhanced bone-resorption in humoral hypercalcemia of malignancy.

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.

Small VCP/p97-interacting protein (SVIP) is involved in various cellular processes, including membrane fusion and ubiquitin-dependent protein degradation. SVIP functions as an inhibitor of the endoplasmic reticulum (ER)-associated degradation (ERAD) pathway. On the other hand, SVIP overexpression increased the levels of p62 protein and enhanced starvation-activated autophagy as well as stimulated sequestration of polyubiquitinated proteins and p62 in autophagosomes.

Synaptotagmin V, (SYT5) is a member of synaptotagmin family, which is a family of type III membrane proteins characterized by cytoplasmic repeats related to protein kinase C regulatory (C2) domains that are considered to bind calcium. Synaptotagmins function as negative regulators of vesicle fusion, allowing fusion in the attendance of calcium, and as calcium receptors or sensor molecules. Among the diseases associated with SYT5 are labyrinthitis, and thyroiditis.

Proliferating cell nuclear antigen (PCNA), a protein of 30 kDa molecular weight also known as cyclin, forms a trimer ring around a DNA double-helix. It binds to a variety of other nuclear proteins and thereby organises biochemical processes at the DNA replication fork. PCNA thereby assumes important functions in DNA synthesis, repair and processing, the regulation of cell cycle and even apoptosis.
Anti-PCNA antibodies occur in systemic lupus, where they represent a rare specificity (< 10 % of SLE patients). However, their presence alone or in combination with other autoantibodies should alert the clinician to the presence of defined or evolving SLE.

TARC cDNA encodes a 94 amino acid precursor protein with a 23 amino acid residue signal peptide that is cleaved off to generate the 71 amino acid residue mature secreted protein. Along with CC chemokine family members, CCL-17 has approximately 24-29% amino acid sequence identity with RANTES, MIP-1a, MIP-1b, MCP-1, MCP-2, MCP-3 and I-309. TARC is expressed in thymus, and at a lower level in the lung, colon, and small intestine. TARC is in addition transiently expressed in stimulated peripheral blood mononuclear cells. Recombinant TARC has been shown to be chemotactic for T cell lines but not monocytes or neutrophils. CCL-17 was recently identified to be a specific functional ligand for CCR4, a receptor that is selectively expressed on T cells. CCL17 is one of quite a few Cys-Cys (CC) cytokine genes clustered on the q arm of chromosome 16. CCL17 shows chemotactic activity for T lymphocytes, but not monocytes or granulocytes. CCL17 binds to chemokine receptors CCR4 and CCR8. This chemokine plays important roles in T cell development in thymus as well as in trafficking and activation of mature T cells.

Interleukin-18 Binding Protein (IL18BP) serves as an inhibitor of the proinflammatory cytokine, IL18. IL18BP binds IL18, inhibits the binding of IL18 to its receptor, and consequently inhibits IL18-induced IFN-gamma production, resulting in reduced T-helper type 1 immune responses. The IL18BP protein is constitutively expressed and secreted in mononuclear cells. Elevated levels of IL18BP protein are detected in the intestinal tissues of patients with Crohn's disease.

TFB1M is a member of the methyltransferase superfamily. TFB1M is a dimethyltransferase which methylates mitochondrial 12S rRNA at the conserved stem loop. The TFB1M protein also is part of the basal mitochondrial transcription complex and is required for mitochondrial gene expression. TFB1M stimulates transcription independently of the methyltransferase activity.

Prefoldin subunit 2 (PFDN2) belongs to the prefoldin beta subunit family. The PFDN2 protein is one of 6 subunits of prefoldin, which is a molecular chaperone complex that binds and stabilizes newly synthesized polypeptides, thus allowing them to fold correctly. PFDN2 binds specifically to cytosolic chaperonin (c-CPN) and transfers target proteins to it. PFDN2 also binds to a nascent polypeptide chain and promotes folding in an setting in which there are many competing pathways for nonnative proteins.

THAP Domain Containing, Apoptosis Associated Protein 11 (THAP11) is a part of the thanatos-associated protein family. THAP11 plays a role as a transcriptional repressor and interacts with HCF1 through a coiled coil domain. THAP11 which is localized to the nucleus and cytoplasm takes part in embryogenesis and pluripotency of embryonic stem cells by recruiting epigenetic modifiers.

TIMP2 belongs to the TIMP gene family. The proteins encoded by this gene family are natural inhibitors of the matrix metalloproteinases, a group of peptidases that take part in degradation of the extracellular matrix. Besides having an inhibitory role against metalloproteinases, the encoded protein has a exclusive part among TIMPfamily members in its capability to directly suppress the proliferation of endothelial cells. Consequently, the encoded protein is crucial to the conservation of tissue homeostasis by suppressing the production of quiescent tissues as an answer to angiogenic factors, and by inhibiting protease activity in tissues undergoing renovation of the extracellular matrix.