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Connective Tissue Growth Factor belongs to the CCN family of proteins. The CCN family presently consists of six members in human also known as: Cyr61 (Cystein rich 61), CTGF (Connective Tissue Growth Factor), Nov (Nephroblastoma Overexpressed gene), WISP-1, 2 and 3 (Wnt-1 Induced Secreted Proteins). The CCN genes encode secreted proteins associated with the Extracellular Matrix (ECM) and cell membrane. CCN proteins are matricellular proteins which are involved in the regulation of various cellular functions including: proliferation, differentiation, survival, adhesion and migration. They are expressed in derivatives of the three embryonic sheets and are implicated in the development of kidney, nervous system, muscle, bone marrow, cartilage and bone. During adulthood, they are implicated in wound healing, bone fracture repair, and pathologies such as: fibrosis, vascular ailments and tumorigenesis.
Full length secreted CCN proteins can show an antiproliferative activity, whereas truncated isoforms are likely to stimulate proliferation and behave as oncogenes. The full length protein consists of four modulesModule I shares partial identity with the N-terminal part of the Insulin-like Growth Factor Binding Proteins (IGFBPs).
Module II includes a stretch of 70amino acid residues – which shares sequence identity with the Von Willebrand Factor Type C repeat (VWC).
Module III contains sequences sharing identity with the Thrombospondin type 1 repeat (TSP1) (WSXCSXXCG), which is thought to be implicated in the binding of sulfated glycoconjugates and to be important for cell adhesion. Module IV, also designated CT, is encoded by exon5. It is the leasts conserved one of the four domains at the level of nucleotide sequence, but it appears to be critical for several of the biological functions attributed to the CCN proteins. Module IV resembles the CT domain of several extracellular protein including, Von Willebrand's factor and mucins. Sequence similarities to heparin-binding motifs are also found within this domain.
Proteolysis of the secreted full-length CCN proteins that has been reported in the case of CCN2 and CCN3 might result in the production of CCN-derived peptides with high affinity for ligands that full-length CNN proteins bind only poorly. Amino-truncated CCN2 isoforms were biologically active whereas no specific biological activity has been attributed to the truncated CCN3. Although the molecular processes underlying the production of these secreted isoforms is presently unknown, it is important to note that proteolysis occur at the same amino acid residues in both CCN2 and CCN3. An elevated expression of CCN2 has also been detected by Northern blotting in human invasive mammary ductal carcinomas, dermatofibromas, pyogenic granuloma, endothelial cells of angiolipomas and angioleiomyomas, and in pancreatic tumors. A study performed with chondrosarcomas representative of various histological grades established that CCN2 expression was closely correlated with increasing levels of malignancy. In agreement with CCN2 playing a role in brain tumor angiogenesis, immunocytochemistry studies indicated that both glioblastoma tumor cells and proliferating endothelial cells stained positive for CCN2. In astrocytomas, CCN2 expression was particularly elevated in high grade tumors, with a marked effect of CCN2 on cell proliferation. Downregulation of CCN2 expression in these cells was associated with a growth arrest at the G1/S transition while over-expression of CCN2 induced a two-fold increase of the number of cells in the G1 phase. Gene profiling analysis allowed to identify a set of about 50 genes whose expression might account for the proliferative activity of CCN2 in these cells. CCN2 was seen in a higher proportion of mononuclear cells of patients with acute lymphoblastic leukemia.

Granulocyte/Macrophage Colony-Stimulating Factors are cytokines that act in hematopoiesis by controlling the production, differentiation, and function of 2 related white cell populations of the blood, the granulocytes and the monocytes-macrophages. CSF-1 induces cells of the monocyte/macrophage lineage. It plays a role in immunological defenses, bone metabolism, lipoproteins clearance, fertility and pregnancy.

The FGFs are a family of more than 20 small (~17–26 kDa) secreted peptides. The initial characterization of these proteins focused on their ability to stimulate fibroblast proliferation. This mitogenic activity was mediated through FGF receptors (FGFRs) 1, 2, or 3. A fourth closely related tyrosine kinase receptor (FGFR4) was able to bind the FGFs but did not lead to a mitogenic response.
FGFs modulate cellular activity via at least 5 distinct subfamilies of high-affinity FGF receptors (FGFRs): FGFR-1, -2, -3, and -4, all with intrinsic tyrosine kinase activity and, except for FGFR-4, multiple splice isoforms, and FGFR-5, which lacks an intracellular kinase domain. There is growing evidence that FGFRs can be important for regulation of glucose and lipid homeostasis. The overexpression of a dominant negative form of FGFR-1 in cells leads to diabetes in mice, which thus implies that proper FGF signaling is required for normal ? cell function and glycemia maintenance. FGFR-2 appears to be a key molecule during pancreatic development. Moreover, FGFR-4 has been implicated in cholesterol metabolism and bile acid synthesis.
FGF-19, has been shown to cause resistance to diet-induced obesity and desensitization and to improve glucose, and lipid profiles in diabetic rodents. Since these effects, at least in part, are mediated through the observed changes in metabolic rates, FGF-19 can be considered as a regulator of energy expenditure.
FGF-21 is preferentially expressed in liver, but an exact knowledge of FGF-21 bioactivity and its mode of action have been lacking to date. FGF-21 is a potent activator of glucose uptake on adipocytes, protects animals from diet-induced obesity when overexpressed in transgenic mice, and lowers blood glucose and triglyceride levels when therapeutically administered to diabetic rodents.

FGF4 holds s comprehensive mitogenic and cell survival activities and takes part in a range of biological processes including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. FGF4 possess oncogenic transforming activity. FGF4 and FGF3, oncogenic growth factors are localized on chromosome 11. Co-amplification of both factors was found in several kinds of human tumors. FGF4 functions in bone morphogenesis and limb development through the sonic hedgehog (SHH) signaling pathway.

RAET1E is a member of the MHC class I family. MHC class I family contains main histocompatibility complex (MHC) class I-related genes positioned in a cluster on chromosome 6q24.2-q25.3. RAET1E and RAET1G protein are different from other RAET1 proteins since they have type I membrane-spanning sequences at their C termini instead glycosylphosphatidylinositol anchor sequences.RAET1E acts as a ligand for NKG2D receptor, expressed on the surface of numerous types of immune cells, involves in innate adaptive immune reactions.RAET1E delivers signals to NK cells and advances tumor immune surveillance by inducing the growth of anti-tumor cytotoxic lymphocyte.

NANOG is a multidomain homeobox transcription factor which functions to maintain the undifferentiated state of pluripotent stem cells. NANOG expression counteracts the differentiation-promoting signals induced by the extrinsic factors LIF, Stat3 and BMP. Once NANOG expression is downregulated, cell differentiation can proceed. Proteins which regulate NANOG expression include transcription factors Oct4, SOX2, FoxD3, and Tcf3 and tumor suppressor p53.

Citrate synthase also known as CS is a Krebs tricarboxylic acid cycle enzyme which catalyzes the synthesis of citrate from oxaloacetate and acetyl coenzyme A. CS is present in almost all cells capable of oxidative metabolism. CS is nuclear encoded and transported into the mitochondrial matrix, where the mature form is found. The diseases related to CS are: critical illness polyneuropathy and mitochondrial cardiomyopathy.

Cytochrome b-c1 complex subunit 2, mitochondrial (UQCRC2) is a member of the peptidase M16 family. UQCRC2 is a component of the ubiquinol-cytochrome c reductase complex (complex III), which is a part of the mitochondrial respiratory chain. UQCRC2 is essential for the compilation of the complex.

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.

GCSF is a cytokine that controls the production, differentiation, and function of granulocytes. The active protein is found extracellularly. 3 transcript variants encoding 3 different isoforms have been found for the GCSF gene. Granulocyte/macrophage colony-stimulating factors are cytokines that take part in hematopoiesis by controlling the production, differentiation, and function of 2 related white cell populations of the blood, the granulocytes and the monocytes-macrophages. This csf induces granulocytes.

SIRT5 belongs to the Sirtuin family of proteins, homologs to the yeast Sir2 protein. Sirtuin family members hold a sirtuin core domain and grouped into four classes. The protein encoded by this gene is included in class III of the sirtuin family. Human sirtuins functions were not yet determined; still, yeast sirtuin proteins are known to regulate epigenetic gene silencing and suppress recombination of rDNA. Studies propose that human sirtuin could operate as intracellular regulatory protein with mono-ADP-ribosyltransferase activity.

FGF-23 is a member of the fibroblast growth factor (FGF) family. FGF family members possess broad mitogenic and cell survival activities and are involved in a variety of biological processes including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. FGF-23 inhibits renal tubular phosphate transport. The FGF-23 gene was identified by its mutations associated with autosomal dominant hypophosphatemic rickets (ADHR), an inherited phosphate wasting disorder. Abnormally high level expression of FGF-23 was found in oncogenic hypophosphatemic osteomalacia (OHO), a phenotypically similar disease caused by abnormal phosphate metabolism. FGF-23 mutations have also been shown to cause familial tumoral calcinosis with hyperphosphatemia.

SIRT3 is a member of a family of proteins called Sirtuin. Proteins of the Sirtuin family are characterized by a Sirtuin core domain and grouped into four classes. The roles of human Sirtuins are numerous and are important in aging prosseses, stress resistance and metabolic regulation. SIRT3 shows NAD+-dependent deacetylase activity in the mitochondria. Over-expression of SIRT3 causes increased levels of the mitochondrial uncoupling protein 1. Also, in certain breast cancers the levels of SIRT3 protein are found to be extremely high.

Myostatin (GDF-8) is expressed uniquely in human skeletal muscle as a 12 kDa mature glycoprotein consisting of 113 amino acid residues and secreted into plasma. Myostatin is a member of the transforming growth factor ? superfamily of secreted growth and differentiation factors that is essential for proper regulation of skeletal muscle mass. Studies have shown that myostatin could play an important role in cardiac development and physiology.

DECR1 is a mitochondrial protein which exists as a homotetramer and is a member of a family of short-chain dehydrogenases/reductases. DECR1 acts as an auxiliary enzyme of beta-oxidation andt partakes in the metabolism of unsaturated fatty enoyl-CoA esters. in particular, DECR1 uses NADP+ to catalyze the reduction of 2,4-dienoyl-CoA to yield trans-3-enoyl-CoA that can subsequently be used as an intermediate in the Krebs cycle. Furthermore, DECR1 is believed to work as a tumor suppressor, possibly downregulating the expression of Neu and slowing the rate of tumorigenesis.

The IGFs comprise a family of peptides that play important roles in mammalian growth and development. IGF1 mediates many of the growth-promoting effects of growth hormone. Early studies showed that growth hormone did not directly stimulate the incorporation of sulfate into cartilage, but rather acted through a serum factor, termed 'sulfation factor,' which later became known as 'somatomedin'. Three main somatomedins have been characterized: somatomedin C (IGF1), somatomedin A, and somatomedin B. IGF-1 is a small protein secreted mostly but not exclusively by the liver and circulating in blood mostly as a complex with several IGF binding proteins. It has growth-regulating, insulin-like, and mitogenic functions and it is secreted in response to growth hormone stimulation.

PDGF-AA, PDGF-BB and PDGF-AB, are potent mitogens for a variety of cell types including smooth muscle cells, connective tissue cells, bone and cartilage cells, and some blood cells. The PDGF is stored in platelet alpha-granules and released upon platelet activation. The PDGF is involved in a number of biological processes, including hyperplasia, chemotaxis, embryonic neuron development, and respiratory tubule epithelial cell development. Two distinct signaling receptors used by PDGF have been identified and named PDGFR-alpha and PDGFR-beta. PDGFR-alpha is high-affinity receptor for each of the three PDGF forms. On the other hand, PDGFR-beta interacts with only PDGF-BB and PDGF-AB.

GDF15 is part of the TGF-Beta superfamily that is involved in regulating inflammatory and apoptotic pathways in injured tissues and throughout disease processes. GDF15 is most abundant in the liver. Its expression in liver can be considerably up-regulated in during injury of organs such as liver, kidney, heart and lung. GDF-15 promotes proliferation or growth arrest and differentiation due to differences in cellular differentiation. GDF15 prevents apoptosis in cerebellar granule neurons by activating Akt and inhibiting endogenously active ERK. GDF15 is a novel autocrine/endocrine factor that antagonizes the hypertrophic response and loss of ventricular performance.

Stem cell factor / KIT ligand (SCF) is a cytokine which binds CD117(c-Kit). SCF is also known as "steel factor" or "c-kit ligand". SCF exists in two forms, cell surface bound SCF and soluble (or free) SCF. Soluble SCF is produced by the cleavage of surface bound SCF by metalloproteases.
SCF is a growth factor important for the survival, proliferation, and differentiation of hematopoietic stem cells and other hematopoietic progenitor cells. One of its roles is to change the BFU-E (burst-forming unit-erythroid) cells, which are the earliest erythrocyte precursors in the erythrocytic series, into the CFU-E (colony-forming unit-erythroid).

DR1 is a phosphoprotein that inhibits both basal and activated levels of transcription. DR1 is phosphorylated in vivo which affects its interaction with TBP. DR1 has a histone fold motif at the amino terminus, a TBP-binding domain, and a glutamine- and alanine-rich region. By selectively repressing polymerases II and III, DR1 alters the physiological balance of transcriptional output in favor of polymerase I.

Vascular endothelial growth factor is an important signaling protein involved in both vasculogenesis and angiogenesis. As its name implies, VEGF activity has been mostly studied on cells of the vascular endothelium, although it does have effects on a number of other cell types (e.g. stimulation monocyte/macrophage migration, neurons, cancer cells, kidney epithelial cells ).VEGF mediates increased vascular permeability, induces angiogenesis, vasculogenesis and endothelial cell growth, promotes cell migration, and inhibits apoptosis. In vitro, VEGF has been shown to stimulate endothelial cell mitogenesis and cell migration. VEGF is also a vasodilator and increases microvascular permeability and was originally referred to as vascular permeability factor.
Elevated levels of this protein is linked to POEMS syndrome, also known as Crow-Fukase syndrome. Mutations in this gene have been associated with proliferative and nonproliferative diabetic retinopathy.

Synaptotagmin-11 (SYT11) protein may be involved in Ca2+-dependent exocytosis of secretory vesicles through Ca2+ and phospholipid binding to the C2 domain or may function as Ca2+ sensors in the process of vesicular trafficking and exocytosis.

Ubiquinol-Cytochrome C Reductase Core Protein I (UQCRC1) is a member of the peptidase M16 family,UQCRC1/QCR1 subfamily. UQCRC1 is a part of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is component of the mitochondrial respiratory chain. UQCRC1 can mediate formation of the complex between cytochromes c and c1.