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Syndecan-4 is a type I integral membrane heparan sulfate proteoglycan (HSPG), which was originally isolated from cloned rat microvascular endothelial cells as an antithrombin-binding molecule, and is now known to be a member of the syndecan family. Syndecan-4 binds to basic fibroblast growth factor (bFGF), midkine, and tissue factor pathway inhibitor via its heparan sulfate chains, and is thought to be involved in various biologic functions such as signaling of bFGF, anticoagulation, and focal adhesion formation. A previous study demonstrated that syndecan-4 is expressed in various tissues, and its level of expression in the kidney is stronger than those of other syndecan family members. Thus, syndecan-4 is thought to play certain roles in maintaining renal function. Moreover, it has been reported that proteoglycans, especially sulfated proteoglycans, are involved in organogenesis of the kidney.

S100P is a Ca2+ binding protein that is part of the S100 family of proteins containing 2 EF-hand calcium-binding motifs. S100 proteins are found in the cytoplasm and/or nucleus of a large range of cells, and participates in the regulation of a number of cellular function such as cell cycle progression and differentiation. S100P participates in numerous biological functions but the exact functions or mechanism of its action is still mostly unknown. Once S100P binds calcium ions it goes through a conformational change that results in an exposure of a hydrophobic surface which permits the interaction with specific target proteins.

Agouti-related protein is an endogenous antagonist of hypothalamic alpha-melanocortin receptors MC3R and MC4R with potent orexigenic activity. Although a complete deletion of the AGRP gene does not produce any significant metabolic phenotypes, reduction in AGRP expression by RNA interference is associated with increased metabolic rate along with reduced weight gain. In hypothalamus, it is produced by neurons in the medial portion of arcuate nucleus, which produce also the potent orexigenic peptide Neuropeptide Y (NP-Y). Another site of central AGRP production is the hypothalamic nucleus. AGRP encompasses 132 amino acid residues and its alpha-melanocortin inhibiting activity results in a 34 amino acid cystine knot domain within the C-terminal (87-132) portion of the protein. Both AGRP and NP-Y expression was shown to be suppressed by leptin. Central administration of AGRP induces hyperphagia and increased gain in body weight in rodents, but may also exert metabolic effects even when hyperphagia is prevented. In the absence of hyperphagia, intracerebralventricular administration of AGRP caused significant increases in plasma leptin and insulin concentrations (twofold and 1.5-fold, respectively) and fat pad mass.
In the periphery, AGRP mRNA was found in adrenal glands, lung, testis, ovary, skeletal muscle and adipose tissue in humans or rodents. In the adrenals, it was shown that AGRP antagonizes glucosteroid production mediated by MC4R. AGRP could then modulate locally the functions of some peripheral tissues such as adrenals.
In human and rat serum, detectable levels of AGRP-like activity were reported in the lower picogram range. The serum AGRP levels were elevated in obese humans compared to lean controls and increased with fasting in rats.

Snail Family Zinc Finger 2 also known as SNAI2 is a member of the snail C2H2-type zinc-finger protein family. SNAI2 acts as a transcriptional repressor which binds to E-box motifs and is as well likely to repress E-cadherin transcription in breast carcinoma. SNAI2 is implicated in epithelial-mesenchymal transitions furthermore, it has antiapoptotic activity.

SNAP23 is a non-neuronal SNAP25 protein homologue and a target SNARE ubiquitously expressed on the plasma membrane and other intracellular membranes. SNAP23 is involved in exocytotic membrane fusion in most cells that do not express SNAP-25. SNAP23 is an essential component of the high affinity receptor for the general membrane fusion machinery and an crucial regulator of transport vesicle docking and fusion. SNAP23 is phosphorylated in platelets through cell activation during a protein kinase C-related mechanism at two or more sites. SNAP23, the ubiqitously expressed homologue of SNAP25, interacts directly with ubiquitous kinesin heavy chain (uKHC). SNAP-23 is expressed in human eosinophils and is a candidates for association with VAMP-2 during docking, which is followed by exocytosis.

MANF is a 20kDa protein which belongs to the ARMET family. MANF was originally known as an arginine-rich region protein which was extremely mutated in a large number of tumors. MANF Expression is induced during ER stress, signifying that MANF takes part in protein quality control during ER stress.

RGS19 is a member of RGS (regulator of G protein signaling) family and negatively regulates G protein coupled receptor signaling. RGS19 protein specifically cooperates with heterotrimeric GTP-binding protein G alpha i3 (GAI3).

Ring Finger Protein 34 (RNF34) has E3 ubiquitin-protein ligase activity. RNF34 has a RINF finger, a motif recognized to be involved in protein-protein and protein-DNA interactions. RNF34 regulates the levels of CASP8 and CASP10 by targeting them for proteasomal degradation. In addition, RNF34 protects cells against apoptosis induced by TNF. RNF34 also binds phosphatidylinositol 5-phosphateand phosphatidylinositol 3-phosphate. Alternatively splicing results in multiple transcript variants encoding distinct isoforms.

Calretinin is an intracellular calcium-binding protein belonging to the troponin C superfamily characterized by a structural motif described as the EF-hand domain. The immunohistochemical detection of calretinin in developing cerebellum is restricted to the later stages indicated by weak staining from week 21 of gestation, in Purkinje and basket cells and in neurons of the dentate nucleus. The intensity of staining increases as the cerebellum matures. In tumors, calretinin has been detected in mesotheliomas and some pulmonary adenocarcinomas.

Desmopressin is the first vasopressin analog with a very high and very specific antidiuretic effect, has been widely used for different therapeutic purposes and is believed to be partly responsible for the formation of memories learning and memory processes. Desmopressin increases urine concentration and decreases urine production. Desmopressin is used to prevent and control excessive thirst, urination, and dehydration.

GDNF promotes the survival and differentiation of neurons in culture, and is able to prevent apoptosis of motor neurons induced by axotomy. The encoded protein is processed to a mature secreted form that exists as a homodimer. The mature form of the protein is a ligand for the product of the RET (rearranged during transfection) protooncogene. In addition to the transcript encoding GDNF, two additional alternative transcripts encoding distinct proteins, referred to as astrocyte-derived trophic factors, have also been described. Mutations in this gene may be associated with Hirschsprung disease.
GDNF enhances survival and morphological differentiation of neurons and increases their high-affinity uptake.

Bone Morphogenetic protein Receptor-1B, also known as BMPR1B belongs to the TKL Ser/Thr protein kinase family. BMPR1Bis on ligand binding, forms a receptor complex consisting of two type II and two type I transmembrane serine/threonine kinases. Type II receptors phosphorylate as well as activate type I receptors which autophosphorylate, afterward bind and activate SMAD transcriptional regulators. BMPR1B is receptor for BMP7/OP-1 as well as GDF5.

Syntaxin is membrane integrated Q-SNARE protein participating in exocytosis. Syntaxin is composed of an N-terminal regulatory domain (Habc), a SNARE domain (known as H3), and a single C-terminal transmembrane domain. The SNARE (H3) domain binds to both synaptobrevin and SNAP-25 forming the core SNARE complex. Synaptic vesicles store neurotransmitters that are released during calcium-regulated exocytosis. The specificity of neurotransmitter release requires the localization of both synaptic vesicles and calcium channels to the presynaptic active zone. Syntaxins function in this vesicle fusion process. Syntaxins also serve as a substrate for botulinum neurotoxin type C, a metalloprotease that blocks exocytosis and has high affinity for a molecular complex that includes the alpha-latrotoxin receptor which produces exocytosis.

KLRB1 has an inhibitory role on natural killer (NK) cells cytotoxicity which are lymphocytes who facilitate cytotoxicity and secrete cytokines subsequent to immune stimulation. Some genes of the C-type lectin superfamily, like the rodent NKRP1 family of glycoproteins, are expressed by NK cells and take part in NK cell function regulation. KLRB1 holds an extracellular domain with a few characteristic motifs of C-type lectins, a transmembrane domain, and a cytoplasmic domain. Due to its external C terminus KLRB1 is considered to be a type II membrane protein.

GH-releasing peptides (GHRPs) are synthetic peptides that like GHRH effect on pituitary somatotrophs to stimulate GH release. The GHRP1 is one of several synthetic met-enkephalin analogs that owns unnatural D-amino acids. They were developed for their growth hormone (GH) releasing activity and called GH secretatogues. They lack opioid activity but are potent stimulators of GH release. These secretatogues are distinct from the growth hormone releasing hormone (GHRH or GHRF) as they share no sequence relation and derive their function through action at a completely different receptor, the ghrelin receptor.

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.

Human Cu/Zn Superoxide Dismutase (SOD) catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. SOD protects the cell against dangerous levels of superoxide. SOD binds copper and zinc ions and is 1 of 3 isozymes accountable for destroying free superoxide radicals in the body. The encoded protein neutralizes supercharged oxygen molecules, which can damage cells if their levels are not controlled.

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.

Persephin is a member of the GDNF ligand subfamily of the TGF-beta superfamily. PSPN encourages the existence and growth of key dopaminergic and motor neurons, as well as taking part in kidney development. Nonetheless, persephin does not support existence of peripheral neurons.

Protein Tyrosine Phosphatase Receptor Type N (PTPRN) is a catalytically inactive protein and a major target of autoimmune response in diabetes mellitus. The long C-terminal intracellular tail covers the majority of autoantibody epitopes. PTPRN is expressed in neural, neuroendocrine and pancreatic islet cells.

GH-releasing peptides (GHRPs) are synthetic peptides that like GHRH effect on pituitary somatotrophs to stimulate GH release. The GHRP5 is one of several synthetic met-enkephalin analogs that owns unnatural D-amino acids. They were developed for their growth hormone (GH) releasing activity and called GH secretatogues. They lack opioid activity but are potent stimulators of GH release. These secretatogues are distinct from the growth hormone releasing hormone (GHRH or GHRF) as they share no sequence relation and derive their function through action at a completely different receptor, the ghrelin receptor.

Glycoprotein Nmb (GPNMB) is a member of the PMEL/NMB family. GPNMB is a type I transmembrane glycoprotein which exhibits homology to the pMEL17 precursor, a melanocyte-specific protein. GPNMB is expressed in the lowly metastatic human melanoma cell lines and xenografts but has no expression in the highly metastatic cell lines. GPNMB might be involved in growth delay and reduction of metastatic potential. GPNMB is up-regulated in a number of cancer cells, including in glioblastoma multiforme. GPNMB is expressed in many melanoma cells, as well as in tissue macrophages, including liver Kuppfer cells and lung alveolar macrophages, in podocytes and in some cells of the ciliary body of the eye (at protein level). GPNMB is hardly detectable in the healthy brain.

TNFR1 belongs to the TNF-receptor superfamily. TNFR1 is a receptor for TNFSF2/TNF-alpha and homotrimeric TNFSF1/lymphotoxin-alpha.
There are 2 types of soluble TNF receptors: sTNFR-I and sTNFR-II, which act to neutralize the biological activities of TNF alpha and TNF beta. The levels of these soluble receptors seem to increase as a result of shedding of the extracellular domains of the membrane bound receptors. TNF-a, TNFR1 and TNFR2 have roles in cellular differentiation. TNFR1 and TNFR2 function in cell type-specific renal injury.
TNFR1 is capable of signaling both cell survival and apoptosis. TNFR1-induced apoptosis requires 2 sequential signaling complexes. TNFR1 is capable of activating NF-kappaB, mediate apoptosis, and function as a regulator of inflammation. Oxidative stress promotes TNFR1 and TNFR2 self-interaction, ligand-independent and enhanced ligand-dependent TNF signaling. TNFR1 contributes to the induction of non-cytocidal TNF effects including anti-viral state and activation of the acid sphingomyelinase. Human TNFR1 has a major region which controls cell surface expression. High levels of soluble TNF receptors are found in the amniotic fluid of pregnant women.
Germline mutations of the extracellular domains of TNFR1 are linked to the autosomal dominant periodic fever syndrome. The impaired receptor clearance is believed to be a mechanism of the disease. Familial hibernian fever (FHF) is caused by defects in TNFRSF1A gene.

TNFR2 belongs to the TNF-receptor superfamily. TNFR2 is receptor with high affinity for TNFSF2/TNF-alpha and approximately 5-fold lower affinity for homotrimeric TNFSF1/lymphotoxin-alpha. TNFR2 mediates the majority of the metabolic effects of TNF-alpha. In addition, knockout studies in mice propose a role for TNFR2 in protecting neurons from apoptosis by stimulating antioxidative pathways. TNFR2 expression might have a significant role in the angiogenesis, tumor cell proliferation and metastasis of Invasive micropapillary carcinoma of the breast.
There are 2 types of soluble TNF receptors: sTNFR-I and sTNFR-II, which act to neutralize the biological activities of TNF alpha and TNF beta. The levels of these soluble receptors seem to increase as a result of shedding of the extracellular domains of the membrane bound receptors. High levels of soluble TNF receptors are found in the amniotic fluid of pregnant women. TNFR2 and TNFR1 form a heterocomplex which mediates the recruitment of 2 anti-apoptotic proteins, c-IAP1 and c-IAP2, which possess E3 ubiquitin ligase activity. IAPs’ function in TNF-receptor signaling is unknown; nevertheless, c-IAP1 is believed to potentiate TNF-induced apoptosis by the ubiquitination and degradation of TNF-receptor-associated factor 2, which mediates anti-apoptotic signals. Oxidative stress promotes TNFR1 and TNFR2 self-interaction, ligand-independent and enhanced ligand-dependent TNF signaling. TNF-a, TNFR1 and TNFR2 have roles in cellular differentiation. TNFR1 and TNFR2 function in cell type-specific renal injury.