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Endonuclease 8-like 2 (NEIL2) is a member of a class of DNA glycosylases homologous to the bacterial Fpg/Nei family. These glycosylases set off the first step in base excision repair by cleaving bases damaged by reactive oxygen species and introducing a DNA strand break through the associated lyase reaction. NEIL2 is involved in base excision repair of DNA damaged by oxidation or by mutagenic agents. NEIL2 has DNA glycosylase activity towards 5-hydroxyuracil and other oxidized derivatives of cytosine with a preference for mismatched double stranded DNA (DNA bubbles). NEIL2 has insignificant or undetectable activity with 8-oxoguanine, thymine glycol, 2-hydroxyadenine, hypoxanthine, and xanthine. NEIL2 also has AP (apurinic/apyrimidinic) lyase activity and creates incisions in the DNA strand. NEIL2 cleaves the DNA backbone by beta-delta exclusion to produce a single-strand break at the site of the removed base with both 3'- and 5'-phosphates. NEIL2 is found in the testis, skeletal muscle, heart, brain, placenta, lung, pancreas, kidney and liver.

Acyl-CoA Thioesterase 8 (ACOT8) is a group of enzymes which catalyze the hydrolysis of acyl-CoAs to the free fatty acid and coenzyme A (CoASH), granting the potential to regulate intracellular levels of acyl-CoAs, free fatty acids and CoASH. ACOT8 mediate Nef-induced down-regulation of CD4. ACOT8 contends with BAAT (Bile acid CoA: amino acid N-acyltransferase) for bile acid-CoA substrate (such as chenodeoxycholoyl-CoA). ACOT8 prefers medium-length fatty acyl-CoAs.

Sialidase 1 (NEU1) is a lysosomal enzyme which cleaves terminal sialic acid residues from substrates such as glycoproteins and glycolipids. In the lysosome, the NEU1 enzyme is part of a heterotrimeric complex in cooperation with beta-galactosidase and cathepsin A. NEU1 gene mutations may lead to sialidosis, a lysosomal storage disease that can be the type 1 (cherry red -myoclonus syndrome or normosomatic type), which is late-onset, or the type 2 (the dysmorphic type), which takes place at an earlier age with increased acuteness.

NEDD8-activating enzyme E1 regulatory subunit (NAE1) is a member of the ubiquitin-activating E1 family. NAE1 binds to the beta-amyloid precursor protein. Beta-amyloid precursor protein is a cell surface protein with signal-transducing properties, and it is believed to have a role in the pathogenesis of Alzheimer's disease. NAE1 participates in a unique ubiquitinylation-related pathway involving the ubiquitin-like molecule NEDD8. Furthermore, the NAE1 protein is essential for cell cycle progression through the S/M checkpoint.

REXO1 is an exonuclease domain-containing protein which binds to Elongin. The Elongin complex stimulates the rate of transcription elongation by RNA polymerase II by suppressing the transient pausing of the polymerase at many sites along the DNA template. REXO1 is composed of 1221 amino acids and its mRNA is ubiquitously expressed. REXO1 is a putative stem cell marker and is highly expressed in embryonic and adult stem cells.

The enzyme Arylsulfatase A, also known as cerebroside-sulfatase, is responsible to break down sulfatides. The main molecule that Arylsulfatase A breaks down is cerebroside 3-sulfate into cerebroside and sulfate. The enzyme is encoded by the ARSA gene in humans. Phosphate can form a covalent bond with the Arylsulfatase A’s active site 3-oxoalanine, thus, inhibits the protein.

ACAA1 is part of the thiolase family of enzymes and is takes part in lipid metabolism. ACAA1 enzyme is localized to the peroxisome and catalyzes the conversion of acyl-CoA and acetyl-CoA to 3-oxoacyl-CoA in the fatty acid oxidation pathway. ACAA1 shows high enzymatic activity in liver, kidney, intestine and white adipose tissue in rats. ACAA1 deficiency causes pseudo-Zellweger syndrome.

Carbonic anhydrases (CAs) are a large family of zinc metalloenzymes which catalyze the reversible hydration of carbon dioxide. These metalloenzymes participate in various biological processes, including respiration, calcification, acid-base balance, bone resorption, and the formation of aqueous humor, cerebrospinal fluid, saliva, and gastric acid. The metalloenzymes exhibit extensive diversity in tissue distribution and in their subcellular localization. Carbonic Anhydrase XI (CA11) is probably a secreted protein, nevertheless, drastic changes at active site residues completely conserved in CA isozymes with catalytic activity, make it unlikely that CA11 has carbonic anhydrase activity. CA11 shares properties in common with 2 other acatalytic CA isoforms, CA VIII and CA X. CA11 is amply expressed in the brain, and may have a general role in the central nervous system.

Kallikrein-3 (KLK3) is a part of the kallikrein-related peptidase family. Kallikreins are a subgroup of serine proteases having various physiological functions. Numerous kallikreins take part in carcinogenesis and some may be prospective cancer and other disease biomarkers. Kallikrein-3 is 1 of the 15 kallikrein subfamily members located in a cluster on chromosome 19 and is a protease present in seminal plasma. KLK3 hydrolyzes semenogelin-1 consequently leading to the liquefaction of the seminal coagulum. KLK3 acts normally in the liquefaction of seminal coagulum, probably by hydrolysis of the high molecular mass seminal vesicle protein. Serum level of the KLK3 protein, called PSA in the clinical setting, is beneficial in the diagnosis and monitoring of prostatic carcinoma.

MAT2A is an important enzyme in cellular metabolism and catalyzes the formation of S-adenosylmethionine (SAMe) from L-methionine and ATP. MAT2A is expressed in extrahepatic tissues. In liver, MAT2A expression associates with growth, dedifferentiation, and cancer. NF-kappa B and AP-1 are necessary for basal MAT2A expression in HepG2 cells and mediate the increase in MAT2A expression in response to TNF-alpha. Up-regulation of MAT2A provides growth improvement and s-adenosylmethionine and methylthioadenosine thus can block mitogenic signaling in colon cancer cells. Lower expression of both MAT2A and MAT2beta and interfere with leptin signaling in liver cancer cells.

MAT2B is part of the methionine adenosyltransferase family. MAT2B catalyzes the biosynthesis of S-adenosylmethionine from methionine and ATP. MAT2B is the regulatory beta subunit of MAT. MAT2B expression in hepatoma cell lines increases DNA synthesis and thus take part in cell proliferation.

Acyl-protein thioesterase 2 (LYPLA2) is lysophospholipase which acts on biological membranes to regulate the multifunctional lysophospholipids. LYPLA2 may hydrolyze fatty acids from S-acylated cysteine residues in proteins such as trimeric G alpha proteins or HRAS.

Proteasome subunit alpha type-2 (PSMA2) is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. PSMA2 is a 20S core alpha subunit of proteasome belonging to the peptidase T1A family. PSMA2 functions as a docking domain for the regulatory particles and exterior gates blocking unregulated access to the inner cavity.

N-acylneuraminate-9-phosphatase (NANP) belongs to the haloacid dehalogenase (HAD) family and is responsible for dephosphorylating N-acylneuraminate 9-phosphate to form N-acylneuraminate (N-acylneuraminate 9-phosphate + H2O = N-acylneuraminate + phosphate). The catalytic activity of NANP is relies on the presence of magnesium and is inhibited by vanadate and calcium, which is typical of the HAD phosphatase family.

Sepiapterin Reductase is an aldo-keto reductase that catalyzes the NADPH-dependent reduction of pteridine derivatives and is essential in the biosynthesis of BH4. Mutations in Sepiapterin Reductase gene result in DOPA-responsive dystonia due to sepiaterin reductase deficiency defined by the presence of sustained involuntary muscle contractions, often leading to abnormal postures. Sepiapterin reductase is part of the short-chain dehydrogenase/reductase family which reduces exogenous carbonyl compounds as well as phenylpropanedione. Sepiapterin reductase is an important enzyme for the biosynthesis of tetrahydrobiopterin, an necessary cofactor for aromatic amino acid hydrolases together with tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis.

Tartrate-resistant acid phosphatase type 5 (ACP5) is involved in osteopontin and bone sialoprotein dephosphorylation. ACP5 is an iron containing glycoprotein which catalyzes the conversion of orthophosphoric monoester to alcohol and orthophosphate. ACP5 expression seems to increase in some pathological states such as Gaucher and Hodgkin diseases, the hairy cell, the B-cell, and the T-cell leukemias. ACP5 is the most basic of the acid phosphatases and is the only form not inhibited by L(+)-tartrate.

Heparanase is an endo β-D-glucuronidase, which degrades heparan sulfate side chains of heparan sulfate proteoglycans (HSPGs) in the extracellular matrix. Heparanase plays an important role in ECM degradation, facilitating the migration and extravasation of tumor cells and inflammatory leukocytes (1,2,3). Upon degradation, heparanase releases growth factors and cytokines that stimulate cell proliferation and chemotaxis (4,5). Heparanase is a heterodimer comprised of a 50 kDa subunit harboring the active site and a 8 kDa subunit. It is produced as a latent 65 kDa precursor and proteolytically processed to its active form (1,6). Heparanase is highly expressed in myeloid leukocytes (i.e. neutrophils) in platelets and in human placenta. Human heparanase was found to be upregulated in various types of primary tumors, correlating in some cases with increased tumor invasiveness and vascularity and with poor prospective survival (7,8).

HIBCH enzyme is in charge of hydrolysis of both HIBYL-CoA and beta-hydroxypropionyl-CoA. Damages in the HIBCH gene linked to 3-hyroxyisobutyryl-CoA hydrolase deficiency. Multiple transcript variants exist as a result of alternative splicing.

Peptidyl-tRNA hydrolase 2 (PTRH2) is a mitochondrial protein. PTRH2 is released during apoptosis from the mitochondria to the cytoplasm. When in the cytoplasm, PTRH2 regulates the function of 2 transcriptional regulators, TLE5 and TLE1, thus promoting caspase-independent cell death. Natural substrates for PTRH2 may be petidyl-tRNAs which drop off the ribosome during protein synthesis.

Vaspin (visceral adipose-specific SERPIN) is a newly identified adipokine, which is a member of serine protease inhibitor family. Vaspin is also a unique insulin sensitizing adipocytokine in obesity. A recent publication indicates that induction of human vaspin mRNA expression in adipose tissue is regulated in a fat depot-specific manner and could be associated with parameters of obesity, insulin resistance, and glucose metabolism.

Angiotensin is an oligopeptide in the blood that causes vasoconstriction, increased blood pressure, and release of aldosterone from the adrenal cortex. It is a powerful dipsogen. It is derived from the precursor molecule angiotensinogen, a serum globulin produced in the liver. It plays an important role in the renin-angiotensin system.
The protein encoded by this gene, pre-angiotensinogen or angiotensinogen precursor, is expressed in the liver and is cleaved by the enzyme renin in response to lowered blood pressure. The resulting product, angiotensin I is then cleaved by angiotensin converting enzyme (ACE) to generate the physiologically active enzyme angiotensin II. The protein is involved in maintaining blood pressure and in the pathogenesis of essential hypertension and preeclampsia.

Carboxyl ester lipase also known as CEL, formely called cholesterol esterase or bile salt-stimulated lipase, is an enzyme with lipolytic capablity of hydrolyzing cholesteryl esters, tri-, di-, and mono- phospholipids, acylglycerol, ceramide and lysophospholipids. The carboxyl terminus of the enzyme controls enzymatic activity by creating hydrogen bonds with the surface loop to partlyshield the active site. The active catalytic site triad of serine-histidine-aspartate is centrally located in the enzyme structure and is partly covered by a surface loop. Bile salt binding to the loop domain set free the active site for accessibility by water-insoluble substrates. CEL is produced mainly in the pancreas and lactating mammary gland, thus the protein is also expressed in liver, macrophages, and in the vessel wall.

Dopa decarboxylase is a homodimeric, pyridoxal phosphate dependent enzyme.
Dopa decarboxylase is involved in 2 metabolic pathways, synthesizing 2 significant neurotransmitters the take part in numerous clinical disorders, including Parkinson’s disease. Dopa decarboxylase is located in different areas of the brain and is mostly found in basal ganglia. Dopa decarboxylase catalyzes the decarboxylation of L-3,4-dihydroxyphenylalanine (DOPA) to dopa, L-5-hydroxytryptophan to serotonin and L-tryptophan to tryptamine. Defects in Dopa decarboxylase leads to aromatic L-amino-acid decarboxylase deficiency (AADCD). AADCD deficiency is an inborn error in neurotransmitter metabolism that causes combined serotonin and catecholamine deficiency.

MAT1A catalyzes a two-step reaction that involves the transfer of the adenosyl moiety of ATP to methionine to form S-adenosylmethionine and tripolyphosphate, which is subsequently cleaved to PPi and Pi. S-adenosylmethionine is the source of methyl groups for most biological methylations. MAT1A is found as a homotetramer (MAT I) or a homodimer (MAT III) whereas a third form, MAT II (gamma), is encoded by the MAT2A gene. Mutations in MAT1A gene are associated with methionine adenosyltransferase deficiency. MAT1A expression also correlates with a differentiated phenotype, whereas liver cells expressing MAT2A present a dedifferentiated phenotype and lowered AdoMet synthesis. Likewise, NFκB and TNFα cause a switch from MAT1A to MAT2A expression in human hepatocellular carcinoma (HCC), which facilitates cancer cell growth.