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Glucagon-like peptide-1 (GLP-1) is derived from the transcription product of the proglucagon gene. The major source of GLP-1 in the body is the intestinal L cell that secretes GLP-1 as a guthormone. The biologically active forms of GLP-1 are: GLP-1-(7-37) and GLP-1-(7-36)NH2.
GLP-1 secretion by L cells is dependent on the presence of nutrients in the lumen of the small intestine. The secretagogues (agents that causes or stimulates secretion) of this hormone include major nutrients like carbohydrate, proteinand lipid. Once in the circulation, GLP-1 has a half life of less than 2 minutes, due to rapid degradation by the enzyme dipeptidyl peptidase-4.
GLP-1 possesses several physiological properties that make it a subject of intensive investigation as a potential treatment of diabetes mellitus. The known physiological functions of GLP-1 include: Increases insulin secretion from the pancreas in a glucose-dependent manner, decreases glucagon secretion from the pancreas, increases beta cells mass and insulin gene expression, inhibits acid secretion and gastric emptying in the stomach, decreases food intake by increasing satiety.

SPARC protein, or secreted protein acidic and rich in cysteine, or osteonectin or basement-membrane protein 40 is a protein that is coded by the SPARC gene in humans. It is a glycoprotein located in bones, that binds to calcium. The osteonectin is secreted from osteoblasts cells when boas are formed, mineralized and promotes the formation and creation of mineral crystals. Asides from calcium, it has been shown that this protein can also bind to collagen.

AHSG (fetuin-A) which is a glycoprotein present in the serum, is synthesized by hepatocytes. AHSG is one of the fetuin class of plasma binding proteins. It is involved in a number of functions, such as endocytosis, brain development and the formation of bone tissue. It is usually present in the cortical plate of the immature cerebral cortex and bone marrow hemopoietic matrix, hence it has been postulated that it participates in the development of the tissues. Yet, its exact significance is still vague. AHSG promotes endocytosis, hold opsonic properties and influences the mineral phase of the bone. Affinity for calcium and barium ions has been shown.

Fetuin is a liver-produced negative acute phase protein composed of two subunits, the A and B chains.
Fetuin homologs have been identified in several species including rat, sheep, pig, rabbit, guinea pig, cattle, mouse and human. Multiple physiological roles for these homologs have been suggested, including ability to bind to hydroxyapatite crystals and to specifically inhibit the tyrosine kinase (TK) activity of the receptor (IR).
Fetuin-A (alpha2-Heremans-Schmid glycoprotein; AHSG) is an important circulating inhibitor of calcification in vivo, and is downregulated during the acute-phase response.
Sera from patients on long-term dialysis with low AHSG concentrations showed impaired ex-vivo capacity to inhibit CaxPO4 precipitation.
Fetuin may influence the resolution of inflammation by modulating the phagocytosis of apoptotic cells by macrophages.
ASHG blocks TGF-beta-dependent signaling in osteoblastic cells, and mice lacking ASHG display growth plate defects, increased bone formation with age, and enhanced cytokine-dependent osteogenesis.

Phospholipase A2 (PLA2) catalyzes the hydrolysis of the sn-2 position of membrane glycerophospholipids to liberate arachidonic acid (AA), a precursor of eicosanoids including prostaglandins and leukotrienes. The same reaction also produces lysophosholipids, which represent another class of lipid mediators.
The secretory PLA2 (sPLA2) family, in which 10 isozymes have been identified, consists of low molecular weight, Ca2+-requiring secretory enzymes that have been implicated in a number of biological processes, such as modification of eicosanoid generation, inflammation, and host defense.
This enzyme has been proposed to hydrolyze phosphatidylcholine (PC) in lipoproteins to liberate lyso- PC and free fatty acids in the arterial wall, thereby facilitating the accumulation of bioactive lipids and modified lipoproteins in atherosclerotic foci.
In mice, sPLA2 expression significantly influences HDL particle size and composition and demonstrate that an induction of sPLA2 is required for the decrease in plasma HDL cholesterol in response to inflammatory stimuli. Instillation of bacteria into the bronchi was associated with surfactant degradation and a decrease in large:small ratio of surfactant aggregates in rats.

Glucagon is an important hormone involved in carbohydrate metabolism. The hormone is synthesized and secreted from alpha cells (?-cells) of the islets of Langerhans, which are located in the endocrine portion of the pancreas. Glucagon is released when the glucose level in the blood is low (hypoglycemia), causing the liver to convert stored glycogen into glucose and release it into the bloodstream. The action of glucagon is thus opposite to that of insulin, which instructs the body's cells to take in glucose from the blood in times of satiation.
Glucagon is beneficial for the culture of some cell types. It has been used in some biochemical regulation studies of glycogenolysis in hepatocytes. It has been also been found to induce DNA replication in primary cultures of adult rat hepatocytes when used in combinations with EGF and Insulin. Glucagon increases the blood glucose concentration by promoting rapid breakdown of liver glycogen, and also acts to relax smooth muscle such as the gastrointestinal tract.

Myelin Oligodendrocyte Glycoprotein is a membrane protein expressed on the oligodendrocyte cell surface and the outermost surface of myelin sheaths. Due to this localization, it is a prime target antigen that plays a role in immune-mediated demyelination. Myelin Oligodendrocyte Glycoprotein is involved in completion and maintenance of the myelin sheath and in cell-cell communication. MOG protein was found to differentially expressed in the dorsolateral prefrontal cortex and in the temporal lobe from patients with schizophrenia. MOG-specific antibody is crucial to the initiation of MOG-induced murine experimental autoimmune encephalomyelitis.

SEPT6 is a member of the septin family of GTPases and is functionally involved in cytokinesis and conservation of cellular morphology. SEPT6 interact with SEPT2. The genes encoding the mixed-lineage leukemia and SEPT2 breakpoint proteins are associated with one type of pediatric acute myeloid leukemia which is caused by reciprocal translocation between chromosomes 11 and X.

SERPINI1 (Neuroserpin) is an inhibitory serpin which is expressed primarily in the central nervous system. Even though the physiological target of SERPINI1 is still vague, amassed evidence suggest that SERPINI1 has an imperative role in controlling proteolytic degradation of extracellular matrix (ECM) during synaptogenesis and the subsequent development of neuronal plasticity. The neuroprotective role of SERPINI1 has been demonstrated in transgenic mice lacking SERPINI1 expression. The deficiency of SERPINI1 in these mice is linked with motor neuron disease characterized by axonal degradation. In humans, defects in SERPINI1, caused by point mutations in the neuroserpin gene, trigger a hereditary disorder known as the familial encephalopathy with neuroserpin inclusion bodies (FENIB).

Cysteine protease ATG4B (ATG4B) belongs to the autophagin protein family. Autophagy is the manner by which endogenous proteins and damaged organelles are destroyed intracellularly. Autophagy is vital for cell homeostasis and cell remodeling during differentiation, metamorphosis, non-apoptotic cell death, and aging. ATG4B is a cysteine protease necessary for autophagy, which cleaves the C-terminal part of either MAP1LC3, GABARAPL2 or GABARAP, allowing the liberation of form I. A subpopulation of form I is then transformed to a smaller form (form II). Form II, with an exposed C-terminal glycine, is deemed to be the phosphatidylethanolamine (PE)-conjugated form, and is capable of binding to autophagosomes. Reduced levels of autophagy are seen in some malignant tumors; therefore autophagy may have a role in controlling the unregulated cell growth linked to cancer.

g-synuclein(Originally known as a breast cancer specific gene product, BCSG1) is an acidic neuronal protein of 127 amino acids. Gamma-Synuclein is a member of the Synuclein protein family, which is believed to be involved in the pathogenesis of neurodegenerative diseases. High levels of Gamma-Synuclein have been found in advanced breast carcinomas suggesting a correlation between overexpression of SNCG and breast tumor development. Synuclein-Gamma is found mostly in the peripheral nervous system (in primary sensory neurons, sympathetic neurons, and motor neurons) and retina. SNCG is also identified in the brain, ovarian tumors, and in the olfactory epithelium. SNCG expression in breast tumors is a marker for tumor progression. A modification in the expression of gamma-synuclein has been detected in the retina of Alzheimer's patients.

Ro 60 kDa autoantigen is an RNA-binding protein that binds to several small cytoplasmic RNA molecules known as Y RNAs. SSA2 may stabilize these RNAs from degradation. Sera taken from patients with Systemic Lupus Erythematosus (SLE) often contains antibodies that react with the normal cellular SSA2 protein as if this antigen was foreign.

Btc is a potent mitogen for retinal pigment epithelial cells and vascular smooth muscle cells. The effects of betacellulin are probably mediated by the egf receptor and other related receptors.

Secreted frizzled-related protein 4 (SFRP4) belongs to the SFRP family which contains a cysteine-rich domain homologous to the putative Wnt-binding site of Frizzled proteins. SFRPs serve as soluble modulators of Wnt signaling. SFRP4 may serve as a regulator of adult uterine morphology and function. SFRP4 increases apoptosis during ovulation possibly via modulation of FZ1/FZ4/WNT4 signaling. SFRP4 also has phosphaturic effects by specifically inhibiting sodium-dependent phosphate uptake. SFRP4 is expressed in proliferative endometrium and several types of ovarian, endometrial and Brest tumors. SFRP4 is expressed in mesenchymal cells and in cardiomyocytes. SFRP4 expression in ventricular myocardium correlates with apoptosis related gene expression. SFRP4 is up-regulated in failing myocardium.

Osteoprotegerin acts as decoy receptor for rankl and thereby neutralizes its function in osteoclastogenesis. OPG inhibits the activation of osteoclasts and promotes osteoclast apoptosis in vitro. Bone homeostasis seems to depend on the local rankl/opg ratio. Osteoprotegerin may also play a role in preventing arterial calcification. May act as decoy receptor for trail and protect against apoptosis. Trail binding blocks the inhibition of osteoclastogenesis.

Thyroxine binding globulin, also known as SERPINA7, is synthesized in the liver and carried in the blood.
SERPINA7 may be decreased or increased in a number of diseases. Its main value in diagnosis is to assess thyroid function by determining the amount of free T3/T4.
Thyroxine binding globulin, binds and transports thyroid hormones in the circulation. SERPINA7 carries the majority of the T3/T4 in the blood. SERPINA7 has only one binding site for T3/T4 and about 25% of Thyroxine binding globulin is usually saturated.

Group IB secretory phospholipase A2 (sPLA2-IB) mediates cell proliferation, cell migration, hormone release and eicosanoid production via its receptor in peripheral tissues. In the CNS, high-affinity binding sites of sPLA2-IB have been documented. sPLA2-IB induced neuronal cell death in a concentrationdependent manner depending on PGD2 metabolites, especially Delta12-PGJ2 that might mediate sPLA2-IB-induced apoptosis. The secretory PLA2 (sPLA2) family, in which 10 isozymes have been identified, consists of lowmolecular weight, Ca2+-requiring secretory enzymes that have been implicated in a number of biological processes, such as modification of eicosanoid generation, inflammation, and host defense.

Secreted frizzled-related protein 2 (SFRP2) belongs to the SFRP family which contains a cysteine-rich domain homologous to the putative Wnt-binding site of Frizzled proteins. SFRP2 function as soluble modulators of Wnt signaling. Methylation of SFRP2 is a possible marker for the existence of colorectal cancer.

ATG5 is a member of the autophagy-related (ATG) genes family. Autophagy is a catabolic process for the autophagosomic-lysosomal degradation of bulk cytoplasmic contents. ATG5 protein is essential for autophagy. It conjugates to ATG12 and associates with isolation membrane to form autophagosomes. In addition ATG5 takes a vital part in the apoptotic process and it is expressed relatively late in the apoptotic process, downstream of caspase activity.

ASRGL1 is a 308 amino acid protein which is a member of the Ntn-hydrolase family. ASRGL1 is an autoantigenic protein which is present in the mid-piece of sperm after obstruction of the male reproductive tract. ASRGL1 is expressed highly in the testis, but is also expressed in the brain, kidney and gastrointestinal tissues. High levels of ASRGL1 are also detected in ovarian, uterine and mammary tumors in comparison with normal tissues of the same origin.

Plasma protease C1 inhibitor (SERPING1) is a part of the serpin superfamily of serine protease inhibitors. SERPING1 plays an important role in regulating activation of both the complement and contact systems. That isdue to the fact that SERPING1 regulates the activation of complement factor C1 in addition to the activity of activated C1 by coupling with the active catalytic site at the light chains of C1r and C1s. SERPING1 insufficiency results in hereditary angioedema, which is characterized by recurrent episodes of localized angioedema of the skin, gastrointestinal mucosa or upper respiratory mucosa.

Zinc-alpha-2-glycoprotein (AZGP1) protein stimulates lipid degradation in adipocytes and causes the massive fat losses linked with various advanced cancers. AZGP1 may bind polyunsaturated fatty acids.

SYT13 belongs to the great synaptotagmin protein family which contain 2 domains: cytoplasmic C terminus with two tandem C2 domains (C2A and C2B) and extracellular N-terminal transmembrane domain. Synaptotogmin family members have dissimilar biochemical properties and developmental profiles, and patterns of tissue distribution. Additionally, Synaptotogmins formulate homo- and heteromeric complexes with each other. Synaptotagmins operate as membrane traffickers in multicellular organisms.