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Alpha 1-microglobulin (A1M) is a lipocalin superfamily member (kernal lipocalins). A1M is a low molecular weight protein component of plasma. A1M is distributed in plasma and extravascular compartments of all organs. Alpha-1 Microglobulin is found in mammals, birds, amphibians and fish. The primary sites of A1M synthesis are the liver and the kidney. Around the opening of the lipocalin pocket three lysyl residues are situated; those residues carry yellow-brown modification derived from the binding and degradation of heme and kynurenin (a tryptophan metabolite). A1-Microglobulin’s reductase and dehydrogenase have broad biological substrate specificity properties due to its’ free cysteine side-chain which is located in a flexible loop. Alpha-1-microglobulin is glycosylated by three separate carbohydrate chains: two complex carbohydrates which are N-linked to asparagines at residues 17 and 96, and the other simple carbohydrate which is O-linked to threonine at position 5. The carbohydrates comprise 22% of the total molecular mass of the protein. The glycosylation varies between species.
A1M exists in two forms- a free form and complexed to other macromolecules: in humans- complexed to immunoglobulin A (IgA), in rat- complexed to alpha-1-inhibitor-3. Free A1M is exceptionally heterogeneous in charge (therefore also known as protein HC), and is found tightly linked to a chromophore. The free Alpha-1-microglobulin is a monomeric protein composed of one 188 residue polypeptide and contains three cysteines, two of which (residues 75 and 173) form a conserved intra-molecular disulphide link. The chromophoric group is covalently bound to the free cysteine residue at position 34. A1M binds retinol as a major ligand, but this is probably distinct from its covalent chromophore.
Half of all human plasma A1M (approximately 0.03mg/ml) forms a 1:1 complex with about 5% of plasma immunoglobulin A. The resulting macromolecular complexes’ molecular weight is 200000, and a plasma concentration of 0.3mg/ml. The complex can exhibit both antibody activity and affect many of the biological actions of free Alpha-1-microglobulin.
Alpha-1-microglobulin was first discovered in pathological human urine.
It was suggested that A1M might be involved in tissue defense against reactive oxygen species, oxidation by heme and kynurenin. Evidence also suggests that A1M functions in the regulation of the immune system. Other functions include inhibition of stimulation of cultured lymphocytes by protein antigens; induction of cell division of lymphocytes, a mitogenic effect that can either be enhanced or inhibited by the action of other plasma components; inhibition of neutrophil granulocyte migration in vitro; and inhibition of chemotaxis.

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.

PDX1 activates insulin, somatostatin, glucokinase, islet amyloid polypeptide and glucose transporter type 2 gene transcription. IPF1 is particularly involved in glucose-dependent regulation of insulin gene transcription. Pancreas Duodenum Homeobox-1 binds preferentially the DNA motif 5'-[ct]taat[tg]-3'. During development, specifies the early pancreatic epithelium, permitting its proliferation, branching and subsequent differentiation. At adult stage, it is required for maintaining the hormone-producing phenotype of the beta-cell.

Glutamyl-TRNA Amidotransferase, Subunit C also known as GATC allows the formation of properly charged Gln-tRNA(Gln) through the transamidation of misacylated Glu-tRNA(Gln) in the mitochondria. The reaction occurs in the attendance of glutamine and ATP through an activated gamma-phospho-Glu-tRNA(Gln). In addition, GATC is subunit of the heterotrimeric GatCAB amidotransferase (AdT) complex, composed of A (QRSL1), B (PET112) and C (GATC) subunits.

Glial cell-derived neurotrophic factor or GDNF is part of the GDNF group of ligands proteins. GDNF has a crucial part in numerous cell mechanisms such as neurite outgrowth, cell differentiation, cell survival and migration of cells. GDNF enhances neurons survival via GFRa receptors (mainly GFRa1). The mentioned neurons can die as a result from Parkinson's disease or ALS (amyotrophic lateral sclerosis). This protein takes part in the development of the spermatogenesis & kidney, also, it has a role in alcohol metabolism as ameliorating.

Gamma-glutamylaminecyclotransferase (A2LD1) is an enzyme which converts gamma-glutamylamines to free amines and 5-oxoproline. A2LD1 demonstrates high activity toward gamma-glutamyl-epsilon-lysine, derived from the breakdown of fibrin and other proteins cross-linked by transglutaminases. A2LD1 assists in the proteolytic degradation of crosslinked fibrin by breaking down isodipeptide L-gamma-glutamyl-L-epsilon-lysine, which is a byproduct of fibrin degradation. The reaction catalyzed by the A2LD1 produces 5-oxo-L-proline and a free alkylamine.

Developmental Pluripotency Associated 3 (DPPA3) is a protein which in mice may serve as a maternal factor during the preimplantation stage of development. In mice, the DPPA3 protein has a role in transcriptional repression, cell division, and maintenance of cell pluripotentiality. In humans, related intronless loci are found on chromosomes 14 and X. DPPA3 is expressed in embryonic stem and carcinoma cells. DPPA3 has a low expression in the testis, ovary and thymus. DPPA3 is highly expressed in testicular germ cell tumors.

PDCD6 is a calcium-binding protein and is a member of the penta-EF-hand protein family. Calcium binding is vital for homodimerization and for conformational changes essential for binding to other protein partners. PDCD6 takes part in T cell receptor-, Fas-, and glucocorticoid-induced programmed cell death. However, tests showed that in mice deficient for PDCD6, apoptosis was not blocked which suggests that PDCD6 is functionally redundant.

The term ‘PDGF’ refers to a family of disulphide bond-linked dimeric isoforms that act as autocrine and paracrine growth factors and are produced by a variety of cell types other than platelets.
They act as potent mitogens for almost all mesenchymally-derived cells. Aberrant expression is involved in certain cancers, fibroproliferative disorders and atherosclerosis. The protein also contributes to wound healing and neural regeneration. There are four members of the PDGF family – PDGF A, PDGF B, PDGF C and PDGF D. Two distinct types of PDGF-A exist – a short form that is soluble and a long form that is retained by the extracellular matrix.

PGAM1 is part of the phosphoglycerate mutase family. PGAM1 is an essential component of glucose and 2,3-BPGA (2,3-bisphosphoglycerate) metabolism and catalyzes the reversible reaction of 3-phosphoglycerate (3-PGA) to 2-phosphoglycerate (2-PGA) in the glycolytic pathway. PGAM1 is a dimeric enzyme containing, in different tissues, different proportions of a slow-migrating muscle (MM) isozyme, a fast-migrating brain (BB) isozyme, and a hybrid form (MB). PGAM1 mutations lead to muscle phosphoglycerate mutase deficiency, a.k.a. glycogen storage disease X.

Phosphoglycolate phosphatase (PGP) is discovered in all tissues including red cells, lymphocytes and cultured fibroblasts (at protein level). PGP is most active in skeletal muscle and cardiac muscle. The catalytic activity of PGP is 2-phosphoglycolate + H2O = glycolate + phosphate. Diseases associated with PGP include tardive dyskinesia and polycystic kidney disease.

CNDP Dipeptidase 2 (CNDP2), is a cytosolic, non-specific dipeptidase which is a part of the peptidase M20A protein family. CNDP2 is a secreted peptidase homologous to M20 peptidases. CNDP2 expresses through all adult and fetal tissue, though, an isoform missing exons 3 and 4 expresses in all fetal tissue in adult liver. Over expression of CPGL-B in hepatocellular carcinoma cells results in significant inhibition of HC cell viability, colony formation, cell invasiveness and tumor configuration.

Scavenger mRNA-decapping enzyme (DCPS) is a member of the HIT family. DCPS is required for the complete degradation of mRNAs, both in normal mRNA turnover and in nonsense-mediated mRNA decay. It was shown that DCPS hydrolyzes the residual m7GpppN cap structure after the complete 3'–5' degradation of the mRNA by the exosome. Furthermore, DCPS releases m7GMP and is incapable of cleaving cap structures attached to a long RNA chain.

DDIT4 has a role in the regulation of reactive oxygen species. DDIT4 is upregulated at the transcriptional level as a reaction to stress due to DNA damage and glucocorticoid treatment. DDIT4 negatively regulates the mammalian target of Rapamycin, a serine/threonine kinase frequently referred to as mTOR. DDIT4 is vital in the coupling of extra- and intracellular cues to mTOR regulation.

DLAT gene encodes component E2 of the multi-enzyme pyruvate dehydrogenase complex (PDC). PDC is located in the inner mitochondrial membrane and catalyzes the conversion of pyruvate to acetyl coenzyme A. The protein product of this gene, dihydrolipoamide acetyltransferase, takes acetyl groups created by the oxidative decarboxylation of pyruvate and transfers them to coenzyme A. Dihydrolipoamide acetyltransferase is the antigen for antimitochondrial antibodies which are found in about 95% of patients with the autoimmune liver disease primary biliary cirrhosis (PBC). In patients who suffer from this illness, activated T lymphocytes attack and destroy epithelial cells in the bile duct where this protein is abnormally distributed and overexpressed. PBC ultimately leads to cirrhosis and liver failure. Mutations in DLAT are also a cause of pyruvate dehydrogenase E2 deficiency which causes primary lactic acidosis in infancy and early childhood.

PDXK converts vitamin B6 to Pyridoxal-5-phosphate (PLP), which is a vital cofactor in the intermediate metabolism of amino acids and neurotransmitters. PDXK is cytoplasmic and probably acts as a homodimer. The biological validity of the alternatively spliced transcript variants has not been determined.

Regulation Of Nuclear Pre-MRNA Domain Containing 1A (RPRD1A) is upregulated in cells overexpressing cyclin-dependent kinase inhibitor p15(INK4b) and may have a part in cell cycle regulation. RPRD1A interacts with phosphorylated C-terminal heptapeptide repeat domain (CTD) of the largest RNA polymerase II subunit POLR2A, and partakes in dephosphorylation of the CTD. RPRD1A May function as a negative regulator of cyclin-D1 (CCND1) and cyclin-E (CCNE1) in the cell cycle.

GCDH is part of the acyl-CoA dehydrogenase family. GCDH is localized in the mitochondrial matrix as a homotetramer of 45-kD subunits. GCDH catalyzes the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA and CO(2) in the degradative pathway of L-lysine, L-hydroxylysine, and L-tryptophan metabolism. GCDH uses electron transfer flavoprotein as its electron acceptor.

The 26S proteasome is a multicatalytic proteinase complex with a well ordered structure composed of two complexes- a 20S core and a 19S regulator. PSMD11 is a non-ATPase subunit of the 19S regulator. The 20S core is composed of four rings of 28 non-identical subunits; two rings are composed of 7 alpha subunits and two rings are composed of 7 beta subunits. The 19S regulator is composed of a base that contains six ATPase subunits and two non-ATPase subunits, and a lid that contains up to ten non-ATPase subunits. Proteasomes are spread throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An indispensable function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides.

Dysbindin domain-containing protein 1 (DBNDD1) is a member of the dysbindin family.

Defensins form a family of microbicidal and cytotoxic peptides made by neutrophils. Members of the defensin family are highly similar in protein sequence. This gene encodes defensin, beta 103A, which has broad spectrum antimicrobial activity and may play an important role in innate epithelial defense.

Phosphoribosylaminoimidazole Carboxylase (PAICS) is an enzyme involved in nucleotide biosynthesis and particularly in purine biosynthesis. PAICS is a bifunctional enzyme containing phosphoribosylaminoimidazole carboxylase activity at its N-terminal region and phosphoribosylaminoimidazole succinocarboxamide synthetase at its C-terminal region. PAICS catalyzes the conversion of 5'-phosphoribosyl-5-aminoimidazole(AIR) into 5'-phosphoribosyl-4-carboxy-5-aminoimidazole (CAIR) as described in the reaction. PAICS catalyzes steps six and seven of purine biosynthesis.

PGAM1 is part of the phosphoglycerate mutase family. PGAM1 is an essential component of glucose and 2,3-BPGA (2,3-bisphosphoglycerate) metabolism and catalyzes the reversible reaction of 3-phosphoglycerate (3-PGA) to 2-phosphoglycerate (2-PGA) in the glycolytic pathway. PGAM1 is a dimeric enzyme containing, in different tissues, different proportions of a slow-migrating muscle (MM) isozyme, a fast-migrating brain (BB) isozyme, and a hybrid form (MB). PGAM1 mutations lead to muscle phosphoglycerate mutase deficiency, a.k.a. glycogen storage disease X.

Growth arrest and DNA Damage-Inducible Protein (GADD45A) binds both Cdks and PCNA. GADD45A is involved in DNA replication and repair. GADD45A stimulates DNA excision repair in vitro and inhibits entry of cells into S phase. GADD45A may serve as a link between p53-dependent cell cycle checkpoint and DNA repair. The GADD45A gene belongs to a group of genes whose transcript levels are increased following stressful growth arrest conditions and treatment with DNA-damaging agents. GADD45A responds to environmental stresses by mediating activation of the p38/JNK pathway via MTK1/MEKK4 kinase. GADD45A binds to proliferating cell nuclear antigen.