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Leucine Aminopeptidase 3 also known as LAP3 is a member of the peptidase M17 family. LAP3 is implicated in the processing as well as regular turnover of intracellular proteins. LAP3 catalyzes the removal of unsubstituted N-terminal amino acids from different peptides. LAP3 is responsible of releasing an N-terminal amino acid, Xaa-|-Yaa-, in which Xaa is preferably Leu, but could be other amino acids including Pro although not Arg or Lys, and Yaa may be Pro. Amino acid amides and methyl esters are as well readily hydrolyzed; however rates on arylamides are exceedingly low.

Mitochondrial methylglutaconyl-CoA hydratase (AUH) is involved in the amino acid degradation pathway by catalyzing the conversion of 3-methylglutaconyl-CoA to 3-hydroxy-3-methylglutaryl-CoA and water. AUH Human is expressed as a single mRNA species of 1.8 kb, and translated as a 40kDa precursor protein which is consequently processed to a 32kDa mature form. AUH has a very low enoyl-CoA hydratase activity. The AUH protein binds to the AU-rich element (ARE), which is a common element found in the 3' UTR of rapidly decaying mRNA such as c-fos, c-myc and granulocyte/ macrophage colony stimulating factor. AU-rich elements are involved in directing RNA to rapid degradation and deadenylation. In addition, AUH is homologous to enol-CoA hydratase, which is an enzyme involved in fatty acid degradation, and has been shown to have intrinsic hydratase enzymatic activity. AUH is therefore a bifunctional chimera between RNA binding and metabolic enzyme activity.

Adenylate kinases play a role in regulating the adenine nucleotide composition within a cell by catalyzing the reversible transfer of phosphate groups among adenine nucleotides. There are 3 types of adenylate kinase isozymes, AK1, AK2, and AK3 in vertebrates. Expression of these isozymes are tissue-specific and developmentally regulated. AK2 is localized in the mitochondrial intermembrane space and is involved in apoptosis. AK2 is mutated in individuals with reticular dysgenesis.

Prostaglandin-H2 D-isomerase (PTGDS) is a glutathione-independent prostaglandin D synthase which catalyzes the conversion of prostaglandin H2 (PGH2) to postaglandin D2 (PGD2). PTGDS is may have vital roles in both maturation and maintenance of the central nervous system and male reproductive system. PTGDS is the most abundant protein in the cerebral spinal fluid and recent evidence suggests that PTGDS acts as a beta-amyloid chaperone and may play a role in the deposition of Ab plaques in Alzheimer’s disease.

Aldo-Keto Reductase Family 7 Member A3 or AKR7A3, is an enzyme, it is part of the detoxification of aldehydes and ketones process. AKR7A3 diminishes the dialdehyde protein-binding form of aflatoxin B1 to the non-binding AFB1 dialcohol. The enzyme takes partin protection of liver from toxic and carcinogenic effects of AFB1, a potent hepatocarcinogen.

Adenylate kinases play a role in regulating the adenine nucleotide composition within a cell by catalyzing the reversible transfer of phosphate groups among adenine nucleotides. There are 3 types of adenylate kinase isozymes, AK1, AK2, and AK3 in vertebrates. Expression of these isozymes are tissue-specific and developmentally regulated. AK2 is localized in the mitochondrial intermembrane space and is involved in apoptosis. AK2 is mutated in individuals with reticular dysgenesis.

COAA is a member of the prokaryotic pantothenate kinase family and it is the first enzyme in the Coenzyme A biosynthetic pathway. COAA phosphorylates pantothenate (vitamin B5) to form 4'-phosphopantothenate. The key factor controlling the intracellular CoA concentration is the regulation of COAA activity by feedback inhibition.

DPP4 also called adenosine deaminase complexing protein-2, and T-cell activation antigen CD26 is a serine exopeptidase and complex enzyme that is expressed on the surface of most cell types. DPPIV is an intrinsic membrane glycoprotein and a serine exopeptidase that cleaves X-proline dipeptides from the N-terminus of polypeptides. DPP4 plays a role in t-cell activation. DPP4 is associated with intracellular signal transduction, apoptosis and involved in tumor biology. There are at least 63 substrates which can bind specifically to DPP4 enzyme including growth factors, chemokines, neuro peptides. Furthermore, DPP4 plays a major role in glucose metabolism by cleaving incretins such as glucose-dependent insulinotropic polypeptide (GIP) and GLP-1.

Ectonucleotide Pyrophosphatase-2, aka ENPP2, a part of the ectonucleotide pyrophosphatasefamily. ENPP2 is able to cut the phosphodiester bond between the alpha and the beta position of triphosphate nucleotides, acting as an ectonucleotide phosphodiesterase producing pyrophosphate, as most members of the ENPP family. It is unlike ENPP-1 and ENPP-3, has weak activity against nucleotides, but shows a lysophospholipase D activity which allows the formation of LPA and choline from lysophosphatidylcholine. As well, ENPP-2 and LPA are involved in several inflammatory-driven diseases such as arthritis and asthma.

Cytosolic and membrane-bound types of GST are encoded by 2 different supergene families. There are 8 classes of the soluble cytoplasmic mammalian GST: alpha, kappa, mu, omega, pi, sigma, theta and zeta. The mu class of enzymes functions in the detoxification of electrophilic compounds, including carcinogens, therapeutic drugs, environmental toxins and products of oxidative stress, by conjugation with glutathione. The genes encoding the mu class of enzymes are arranged in a gene cluster on chromosome 1p13.3 and aare highly polymorphic. These genetic differences can change an individual's resistance to carcinogens and toxins as well as affect the toxicity and efficacy of certain drugs. Null mutations of this class mu gene have been linked with the rise in a number of cancers.

LCMT1 is a member of the LCMT family, methyltransferase superfamily. LCMT1 catalyzes the methylation of the carboxyl group of the C-terminal leucine residue (leu309) of the catalytic subunit of protein phosphatase-2A to form alpha-leucine ester residues.

Dimethylarginine dimethylaminohydrolase 1, is a part of the Dimethylarginine Dimethylaminohydrolase gene family. DDAH1 participates in nitric oxide generation by regulating cellular concentrations of methylarginines, that in turn inhibit nitric oxide synthase activity. Deficiency of DDAH1 results in ADMA (asymmetric dimethylarginine) increase and a decrease in cGMP generation.

UBE2E3 or Ubiquitin-conjugating enzyme E2 E3 is part of the E2 ubiquitinconjugating enzyme family. UBE2E3 is needed for the destruction of mitotic cyclins and for cell cycle progression. The ubiquitination process covalently attaches to a short protein of 76 amino acids called ubiquitin, to a lysine residue on the target protein. When a protein has been tagged with one ubiquitin molecule, other rounds of ubiquitination form a polyubiquitin chain that is recognized by the proteasome's 19S regulatory particle, triggering the ATP-dependent unfolding of the target protein which grants passage into the proteasome's 20S core particle, where proteases degrade the target into short peptide fragments for recycling by the cell.

PTGES2 is a membrane-associated prostaglandin E synthase, which catalyzes the conversion of prostaglandin H2 to prostaglandin E2. Additionally, PTGES2 activates the transcription regulated by a gamma-INF-activated transcription element. PTGES2 is widely expressed- in the heart, including apex, inter-ventricular septum, both atria and ventricles, but not in the aorta. PTGES2 is also expressed in fetal heart. PTGES2 is detected in various regions of the brain: cerebellum; occipital, frontal and parietal lobes. It is also expressed in the lymph nodes, skeletal muscle, kidney and trachea, but not in the thymus or lung. PTGES2 is overexpressed in colorectal cancer.

GSTO1 belongs to the theta class glutathione S-transferase-like (GSTTL) protein family. GSTO1 is expressed in a broad array of human tissues and exhibits glutathione-dependent thiol transferase and dehydroascorbate reductase activities as well as catalyzing the reduction of monomethylarsonate which is an intermediate in the pathway of arsenic biotransformation. Furthermore, GSTO1 shields from oxidative stress which is a risk factor for Alzheimer disease, vascular dementia and stroke. GSTO1 is abundant in alveolar macrophages and airway secretions, with the levels reduced in chronic obstructive pulmonary disease patients. In mouse, the GSTO1 protein acts as a small stress response protein, probably involved in cellular redox homeostasis.

Ubiquitin-conjugating enzyme E2 R2 (UBE2R2) is a member of the ubiquitin-conjugating enzyme family. Protein kinase CK2 is a ubiquitous and pleiotropic Ser/Thr protein kinase implicated in cell growth andtransformation. This protein is a protein similar to the E2 ubiquitin conjugating enzyme UBC3/CDC34. Studies propose that CK2-dependent phosphorylation of this ubiquitin-conjugating enzyme functions by regulating beta-TrCP substrate recognition and induces its interaction with beta-TrCP, enhancing beta-catenin degradation. UBE2R2 receives ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. In vitro catalyzes monoubiquitination and 'Lys-48'-linked polyubiquitination. UBE2R2 may be implicated in degradation of katenin. Among the diseases associated with UBE2R2 are cblc, and herpes simplex.

Pin 1 is a peptidyl-prolyl cis/trans isomerase (PPIase) which interacts with NIMA and essential for cell cycle regulation Pin1 is nuclear PPIase containing a WW protein interaction domain, and is structurally and functionally related to Ess1/Ptf1, an essential protein in budding yeast. PPIase activity is necessary for Ess1/Pin1 function in yeast. Pin1 is thus an essential PPIase that regulates mitosis presumably by interacting with NIMA and attenuating its mitosis-promoting activity. Substrates of Pin1 include the mitotic regulators (Cdc25 phosphatase and NIMA, PLK I, Wee, and Myt1 kinases), several transcription factors like b-Catenin, c-Jun, and the tumor suppressor protein p53, and some specific proteins like the RNA Pol II, the cytoskeleton protein tau, and the G1/S protein Cyclin D1.

SAE1 and SAE2 form heterodimers which take part in the posttranslational modification of proteins (sumoylation). This process regulates protein structure as well as intracellular localization of the target. SAE1/SAE2 may indicate on dermatomyositis (DM) as autoantibodies against those 2 proteins have been found in patients.

Pyrroline-5-carboxylate reductase 2 isoform 1 (PYCR2) is a member of the pyrroline-5-carboxylate reductase family. PYCR2 protein catalyzes the conversion of pyrroline-5-carboxylate to proline, which is the last step in proline biosynthesis. The three substrates of the PYCR2 enzyme are L-proline, NAD+, and NADP+, while its four products are 1-pyrroline-5-carboxylate, NADH, NADPH, and H+.

Ubiquitin Conjugating Enzyme E2Q2 (UBE2Q2) is a protein coding gene which receives ubiquitin from the E1 complex and catalyzes its covalent attachment to various proteins. UBE2Q2 which is a part of the ubiquitin-conjugating enzyme family is detected in hypopharyngeal head and neck squamous cell carcinoma and in tumor masses.

PARP1 takes part in the base excision repair pathway, by catalyzing the poly ADP-ribosyl of a restricted number of acceptor proteins involved in chromatin architecture and in DNA metabolism.. PARP1 mediates the poly ADP-ribosy of APLF and CHFR. PARP1 positively regulates the transcription of MTUS1 and negatively regulates the transcription of MTUS2/TIP150. PARP1 is a chromatin-associated enzyme, poly (ADP-ribosyl) transferase, which modifies various nuclear proteins by poly ADP-ribosyl. PARP1 takes part in the regulation of various significant cellular processes such as differentiation, proliferation, and tumor transformation and also in the regulation of the molecular events involved in the recovery of cell from DNA damage. PARP1 is a site of mutation in Fanconi anemia, and is involved in the pathophysiology of type I diabetes.

Dual specificity phosphatase 18 (DUSP18) belongs to the dual-specificity phosphatase (DSP) family, which catalyzes dephosphorylation of phosphotyrosine and phosphothreonine residues. DUSP18 has a preferential enzymatic activity for phosphorylated tyrosine residues over threonine residues, in addition DUSP18 dephosphorylates p-nitrophenyl phosphate (pNPP) in vitro. Furthermore, DUSP18 is inhibited by iodoarectic acid and is activated by manganese ions. DUSP18 is extensively expressed with the highest levels in the liver, brain, ovary and testis.

UBE2T is part of the E2 ubiquitin-conjugating enzyme family that participates in the protein degradation pathway. UBE2T catalyzes the ATP-dependent attachment of ubiquitin to target proteins, thus tagging them for subsequent destruction by the proteasome. UBE2T is an important factor of the Faconi anemia pathway of DNA damage repair and, upon self-inactivation, may negatively regulate the Faconi pathway.