Down syndrome critical region gene 1, also known as DSCR1, is a protein that in humans is encoded by the RCAN1 gene. [5]
Down syndrome critical region gene 1, also known as DSCR1, is a protein that in humans is encoded by the RCAN1 gene. [5]
DSCR1 in human is located at the centromeric border of the DSCR and encodes an inhibitor of calcineurin/ NFAT (nuclear factor activated T cells) signalling. [6]
DSCR1 genomic sequence of total 45 kb contain 7 exons and 6 introns , different cDNA analysis yield first four exons are alternative and code for two isoforms of 197 amino acids, and one isoform code for 171 amino acids which differ in their N terminal . While the rest of the 168 residues are common. There is also alternative promoter region with about 900 bp between exon 3 and 4 suggesting that the fourth isoform might be penetrated from another promoter. [7]
The protein encoded by this gene interacts with calcineurin A and inhibits calcineurin-dependent signaling pathways of genetic transcription, possibly affecting central nervous system development. Three transcript variants encoding three different isoforms have been found for this gene. [5] In endothelial cells, VEGF stimulates RCAN1.4 expression which regulates gene expression, cell migration and tubular morphogenesis. [8]
DSCR1 Consist of putative functional motifs and calcineurin binding domain. DSCR1 contains two proline-rich SH3 binding domain, usually named proline-rich domain (PRD), which defines the protein family. SH3 domains or PRD are very important to allow the binding of the protein to endocytosis-related proteins such as ITSN1 and amphiphysin 1 and 2. [9]
This gene is located in the minimal candidate region for the Down syndrome phenotype, and is overexpressed in the brain of Down syndrome fetuses. Chronic overexpression of this gene may lead to neurofibrillary tangles such as those associated with Alzheimer's disease. [5] [10] RCAN1 helps coordinate whole-body metabolism and can be an important target in treatment of obesity. [11]
All Down syndrome (DS) patients develop neuropathological changes identical to the pathogenesis of Alzheimer's disease (AD) in middle age, such as neuritic plaques and neuronal loss. Therefore, DS patients are perfect models to study AD pathogenesis. [12] Chronic DSCR1 overexpression is related with DS and AD, [13] while its shortage is reported in Huntington's disease. [14] DSCR1 expressed excessively in the Central Nervous System of embryos, and the protein is later overexpressed in brains of DS patients. However, neurotrophic peptide PACAP (or Pituitary adenylate cyclase-activating peptide) which is responsible for the development, differentiation, and survival, and various parts of memory and learning, targets RCAN1, a Down syndrome related gene, induces the expression of regulator of calcineurin 1, through activation of the PKA-CREB pathway, and this is important to understand the mechanisms of neural differentiation and aim for proper expression of RCAN1. [15]
It is suggested that the reason patients with Down syndrome are less predisposed to certain cancers is due to the impact of this gene of reducing blood supply to tumour cells. [16] It is also proposed by epidemiological studies that DS patients are in greater risk of leukaemia, on the other hand they are at lower risk of cancer and other angiogenesis related diseases such as diabetic retinopathy and atherosclerosis, indicating that one or more trisomic genes on chromosome 21 is responsible for protecting DS patients against cancer, and this cancer defence could be a result of angiogenesis suppression. [16]
DSCR1 has been shown to interact with Calcineurin. [17]
Hydrogen peroxide (H2O2) increases the overexpression of protein RCAN1. However, anti-oxidants and inhibitors of mitogen-activated protein kinases (MAPK) treatment block the increased expression of RCAN1 by H2O2. Demonstrating that the increased expression is a result of generating reactive oxygen species and activation of MAPK. Furthermore, phosphorylation is important to regulator RCAN1 protein expression. Because phosphorylation of RCAN1 expression by H2O2 increases of the half-life of the protein. [18]
Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature mainly by processes of sprouting and splitting, but processes such as coalescent angiogenesis, vessel elongation and vessel cooption also play a role. Vasculogenesis is the embryonic formation of endothelial cells from mesoderm cell precursors, and from neovascularization, although discussions are not always precise. The first vessels in the developing embryo form through vasculogenesis, after which angiogenesis is responsible for most, if not all, blood vessel growth during development and in disease.
Calcineurin (CaN) is a calcium and calmodulin dependent serine/threonine protein phosphatase. It activates the T cells of the immune system and can be blocked by drugs. Calcineurin activates nuclear factor of activated T cell cytoplasmic (NFATc), a transcription factor, by dephosphorylating it. The activated NFATc is then translocated into the nucleus, where it upregulates the expression of interleukin 2 (IL-2), which, in turn, stimulates the growth and differentiation of the T cell response. Calcineurin is the target of a class of drugs called calcineurin inhibitors, which include ciclosporin, voclosporin, pimecrolimus and tacrolimus.
Vascular endothelial growth factor, originally known as vascular permeability factor (VPF), is a signal protein produced by many cells that stimulates the formation of blood vessels. To be specific, VEGF is a sub-family of growth factors, the platelet-derived growth factor family of cystine-knot growth factors. They are important signaling proteins involved in both vasculogenesis and angiogenesis.
An angiogenesis inhibitor is a substance that inhibits the growth of new blood vessels (angiogenesis). Some angiogenesis inhibitors are endogenous and a normal part of the body's control and others are obtained exogenously through pharmaceutical drugs or diet.
Endostatin is a naturally occurring, 20-kDa C-terminal fragment derived from type XVIII collagen. It is reported to serve as an anti-angiogenic agent, similar to angiostatin and thrombospondin.
Receptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase proteins. Receptor tyrosine kinases have been shown not only to be key regulators of normal cellular processes but also to have a critical role in the development and progression of many types of cancer. Mutations in receptor tyrosine kinases lead to activation of a series of signalling cascades which have numerous effects on protein expression. Receptor tyrosine kinases are part of the larger family of protein tyrosine kinases, encompassing the receptor tyrosine kinase proteins which contain a transmembrane domain, as well as the non-receptor tyrosine kinases which do not possess transmembrane domains.
Growth differentiation factor 2 (GDF2) also known as bone morphogenetic protein (BMP)-9 is a protein that in humans is encoded by the GDF2 gene. GDF2 belongs to the transforming growth factor beta superfamily.
72 kDa type IV collagenase also known as matrix metalloproteinase-2 (MMP-2) and gelatinase A is an enzyme that in humans is encoded by the MMP2 gene. The MMP2 gene is located on chromosome 16 at position 12.2.
ROCK1 is a protein serine/threonine kinase also known as rho-associated, coiled-coil-containing protein kinase 1. Other common names are ROKβ and P160ROCK. ROCK1 is a major downstream effector of the small GTPase RhoA and is a regulator of the actomyosin cytoskeleton which promotes contractile force generation. ROCK1 plays a role in cancer and in particular cell motility, metastasis, and angiogenesis.
Sphingosine-1-phosphate receptor 1, also known as endothelial differentiation gene 1 (EDG1) is a protein that in humans is encoded by the S1PR1 gene. S1PR1 is a G-protein-coupled receptor which binds the bioactive signaling molecule sphingosine 1-phosphate (S1P). S1PR1 belongs to a sphingosine-1-phosphate receptor subfamily comprising five members (S1PR1-5). S1PR1 was originally identified as an abundant transcript in endothelial cells and it has an important role in regulating endothelial cell cytoskeletal structure, migration, capillary-like network formation and vascular maturation. In addition, S1PR1 signaling is important in the regulation of lymphocyte maturation, migration and trafficking.
Neuropilin-1 is a protein that in humans is encoded by the NRP1 gene. In humans, the neuropilin 1 gene is located at 10p11.22. This is one of two human neuropilins.
Pigment epithelium-derived factor (PEDF) also known as serpin F1 (SERPINF1), is a multifunctional secreted protein that has anti-angiogenic, anti-tumorigenic, and neurotrophic functions. Found in vertebrates, this 50 kDa protein is being researched as a therapeutic candidate for treatment of such conditions as choroidal neovascularization, heart disease, and cancer. In humans, pigment epithelium-derived factor is encoded by the SERPINF1 gene.
Placental growth factor(PlGF) is a protein that in humans is encoded by the PGF gene.
C-fos-induced growth factor (FIGF) is a vascular endothelial growth factor that in humans is encoded by the FIGF gene.
Vascular endothelial growth factor B also known as VEGF-B is a protein that, in humans, is encoded by the VEGF-B gene. VEGF-B is a growth factor that belongs to the vascular endothelial growth factor family, of which VEGF-A is the best-known member.
RCAN2 is a gene that in humans encodes for the protein Calcipressin-2.
Angiogenic factor with G patch and FHA domains 1 is a protein that in humans is encoded by the AGGF1 gene.
Vascular endothelial growth factor A (VEGF-A) is a protein that in humans is encoded by the VEGFA gene.
Angiogenesis is the process of forming new blood vessels from existing blood vessels, formed in vasculogenesis. It is a highly complex process involving extensive interplay between cells, soluble factors, and the extracellular matrix (ECM). Angiogenesis is critical during normal physiological development, but it also occurs in adults during inflammation, wound healing, ischemia, and in pathological conditions such as rheumatoid arthritis, hemangioma, and tumor growth. Proteolysis has been indicated as one of the first and most sustained activities involved in the formation of new blood vessels. Numerous proteases including matrix metalloproteinases (MMPs), a disintegrin and metalloproteinase domain (ADAM), a disintegrin and metalloproteinase domain with throbospondin motifs (ADAMTS), and cysteine and serine proteases are involved in angiogenesis. This article focuses on the important and diverse roles that these proteases play in the regulation of angiogenesis.
In molecular biology, the calcipressin family of proteins negatively regulate calcineurin by direct binding. They are essential for the survival of T helper type 1 cells. Calcipressin 1 is a phosphoprotein that increases its capacity to inhibit calcineurin when phosphorylated at the conserved FLISPP motif; this phosphorylation also controls the half-life of calcipressin 1 by accelerating its degradation.
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