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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.

Dynein light chain roadblock-type (DYNLRB1) belongs to the roadblock dynein light chain family and encodes a cytoplasmic protein which is capable of binding intermediate chain proteins. Upregulation of the DYNLRB1 gene is linked with hepatocellular carcinomas, suggesting that DYNLRB1 may be involved in tumor progression.

Iduronate 2-Sulfatase also known as IDS, belongs to the highly-conserved sulfatase family of enzymes which catalyze the hydrolysis of O-sulfate and N-salfate esters from a variety of substrates. IDS is essential for the lysosomal degradation of the glycosaminoglycans (GAG) heparan sulfate as well as dermatan sulfate. Furthermore, IDS hydrolyzes the 2-sulfate group of the IDS units of the GAG.

Serine/threonine/tyrosine-interacting protein (STYX) is a member of the protein-tyrosine phosphatase family. STYX contains a Gly residue instead of a conserved Cys residue in the dsPTPase catalytic loop which makes it catalytically inactive as a phosphatase. On the other hand, the binding pocket is adequately preserved to bind phosphorylated substrates, and may protect them from phosphatases. STYX may have a role in spermiogenesis. STYX is a possible pseudophosphatase.

SUMF1 is a member of the SUMF family. SUMF1 catalyzes the hydrolysis of sulfate esters by oxidizing a cysteine residue in the substrate sulfatase to an active site 3-oxoalanine residue called C-alpha-formylglycine. Alterations in this gene result in multiple sulfatase deficiency which is a lysosomal storage disorder.

PDIA6 belongs to the protein disulfide isomerase family (PDI). PDIA6 is an enzyme in the endoplasmic reticulum in eukaryotes or periplasmic space of prokaryotes which catalyzes the formation and breakage of disulfide bonds between cysteine residues within proteins as they fold. PDIA6 functions as a chaperone that inhibits aggregation of misfolded proteins. PDIA6, also has a role in platelet aggregation and activation by agonists such as convulxin, collagen and thrombin.

PSMA6 belongs to the peptidase T1A family, which is a 20S core alpha subunit. The proteasome is a multicatalytic proteinase complex with an extremely organized ring-shaped 20S core structure. The core structure consists of 4 rings of 28 non-identical subunits; 2 rings consist of 7 alpha subunits and 2 rings consist of 7 beta subunits. PSMA6 is spread all over eukaryotic cells in large quantities and cleave peptides in an ATP/ubiquitin-dependent procedure in a non-lysosomal pathway.

Threonyl-tRNA synthetase, cytoplasmic (TARS) is a member of the class-II aminoacyl-tRNA synthetase family. The main role of TARS is in tRNA aminoacylation. The N-terminal domain of the TARS enzyme is responsible for the competition with the ribosome whereas the catalytic and the C-terminal domain are involved in binding the 2 anticodon arm-like structures in the operator.

NAA10 is a member of the acetyltransferase family. NAA10 interacts with NAA15, HIF-1 and with the ribosome. In its binding to HIF-1, NAA10 functions as a protein acetyltransferase by regulating its stability. In various cell lines, NAA10 is downregulated in response to hypoxia. NAA10 is expressed during the course of the development of the brain.

Set 7/9 is a histone methyltransferase (HMTase) that transfers methyl groups to Lys4 of histone H3, in complex with S-adenosyl-L-methionine (AdoMet). The methylation of lysine residues of histones plays a critical role in the regulation of chromatin structure and gene expression.
Acetylation, phosphorylation and methylation of the amino-terminal tails of histone are thought to be involved in the regulation of chromatin structure and function. The enzymes identified in the methylation of specific lysine residue on histones belong to the SET family with just one exception. Set7/9, unlike most other SET proteins, is exclusively a mono-methylase.

FEN1 removes 5'' overhanging flaps in DNA repair and processes the 5'' ends of Okazaki fragments in lagging strand DNA synthesis. The interaction between FEN1 and AP endonuclease 1 during long-patch base excision repair provides coordinated loading of the proteins onto the substrate, therefore passing the substrate from one enzyme to another. FEN1 is part of the XPG/RAD2 endonuclease family and is one of ten proteins essential for cell-free DNA replication. DNA secondary structure can inhibit flap processing at certain trinucleotide repeats in a length-dependent manner by concealing the 5'' end of the flap that is necessary for both binding and cleavage by the protein encoded by this gene. Therefore, secondary structure can deter the protective function of this protein, leading to site-specific trinucleotide expansions.

IMP2 Inner Mitochondrial Membrane Peptidase-Like (IMMP2L) is implicated in processing the signal peptide sequences, IMMP2L is used to direct mitochondrial proteins to the mitochondria. IMMP2L resides in the mitochondria and is one of the essential proteins for the catalytic activity of the mitochondrial inner membrane peptidase (IMP) complex. Two variants which encode the same protein have been found for IMMP2L.

The proteasome is a multicatalytic proteinase complex which holds an extremely organized 20S core structure shaped like a ring. The central structure is assembled from 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. There is a high concentration of proteasomes all over the eukaryotic cells and their job is to cleave peptides in an ATP/ubiquitin-dependent procedure in a non-lysosomal pathway. PSMA3 encodes several of the peptidase T1A family which is a 20S core alpha subunit. Two alternative transcripts encoding diverse isoforms were recognized.

PRCP is a plasma protein which takes part in the cleavage of C-terminal amino acids linked to proline in proteinfor example angiotensin-2 & 3 at acidic pHenvironment rather than at neutral pHwhich exhibit less activity. This cleavage is important since Angiotensin-2 takes part in regulation of blood pressure & electrolyte balance which is essential to hypertension.

Glucuronidase Beta (GUSB) is a lysosomal hydrolase which is taking part in the stepwise degradation of glucuronic acid-containing glycosaminoglycans and plays a significant role in the degradation of dermatan and keratin sulfates. GUSB is comprised of heparin sulfate, chondroitin sulfate and hyaluronan.

YOD1 is a Hydrolase which removes conjugated ubiquitin from proteins and takes part in endoplasmic reticulum-associated degradation (ERAD) for misfolded lumenal proteins. YOD1 is a highly conserved deubiquitinating enzyme belonging to the ovarian tumor (otubain) family, whose function has yet to be determined in mammalian cells. YOD1 is a component of a multiprotein complex with p97 as its nucleus, proposing a functional link to a pathway responsible for the dislocation of misfolded proteins from the endoplasmic reticulum. YOD1 variant xpression deprived of its deubiquitinating activity compels a halt on the dislocation reaction, as concluded by the stabilization of various dislocation substrates.

The enzyme Carbonic anhydrase II having an accession number of NP_414668 is also called carbonate dehydratase which is part of the enzyme family that catalyses rapid inter-conversion of carbon dioxide & water to bicarbonate, carbonic acid and protons (CO2 + H2O ? HCO3? + H+), a reaction that occurs rather slowly in the absence of a catalyst. The majority of carbonic anhydrases enclose a zinc ion in their active site and therefore is classified as metalloenzymes.
The most important function of Carbonic anhydrase is known to preserve acid-base balance in blood and other tissues, and to help transport carbon dioxide of tissues. Carbonic anhydrases have been found in all kingdoms of life. Carbonic anhydrase has 3 different classes: alpha, beta and gamma which share very little sequence or structural similarity, thus far they all perform the same function and require a zinc ion at the active site. Mammalian carbonic anhydrase is monomeric and belongs to the alpha class. Plant carbonic anhydrase is dimeric and belongs to the beta class.
Methane-producing bacteria carbonic anhydrase is trimeric and grows in hot springs which forms the gamma class.

DUSP3 belongs to the dual specificity protein phosphatase subfamily which inactivates their target kinases by dephosphorylating both the phosphoserine/threonine and phosphotyrosine residues. DUSP3 negatively regulate members of the mitogen-activated protein kinase superfamily that are related to cellular proliferation and differentiation. DUSP3 is expressed in both breast and ovarian tissues and displays activity both for tyrosine-protein phosphate and serine-protein phosphate, but exhibits a strong preference toward phosphotyrosines, specifically dephosphorylates and inactivates ERK1 and ERK2.

Kallikrein-3 (KLK3) belongs to the kallikrein-related peptidase family. Kallikreins are a subgroup of serine proteases having various physiological functions. Numerous kallikreins are involved 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 is assumed to act 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.

Alanyl-tRNA synthetase is a member of the aminoacyl-tRNA synthetase family, key enzymes of protein biosynthesis which charge tRNA molecules with the respective amino acids. This 108 kDa protein is an autoantigen recognized by PL-12 antibodies which occur in a subset of patients with polymyositis and dermatomyositis. Preliminary data suggest that epitope spreading occurs in the autoimmune PL-12 response such that even antibodies to an isolated alanyl-tRNA molecule can develop.

Histone deacetylase 8 (HDAC8) is a member of the class 1 of the histone deacetylase/acuc/apha family. HDAC8 is biologically involved in skull morphogenesis and metabolic control of the ERR-alpha/PGC1-alpha transcriptional complex. Histones play a key role in transcriptional regulation, cell cycle progression, and developmental events. Histone acetylation/deacetylation modifies chromosome structure and affects transcription factor access to DNA.

Seryl-tRNA synthetase, cytoplasmic (SARS) is a member of the class-II aminoacyl-tRNA synthetase family. Aminoacyl-tRNA synthetases’ role is to catalyze the aminoacylation of tRNAs by their corresponding amino acids, as a result linking amino acids with tRNA-contained nucleotide triplets. The SARS enzyme catalyzes the attachment of serine to tRNA (Ser). SARS enzyme is probably able to aminoacylate tRNA (Sec) with serine, to form the misacylated tRNA L-seryl-tRNA (Sec), which will be then converted into selenocysteinyl-tRNA (Sec).

Sialic acid-binding Ig-like lectin 6 isoform 1 (SIGLEC6) is a member of immunoglobulin superfamily and SIGLEC (sialic acid binding Ig-like lectin) family. SIGLEC6 mediates sialic-acid dependent binding to cells and binds to alpha-2, 6-linked sialic acid. The SIGLEC6 protein localizes in numerous compartments such as membrane fraction, extracellular region and so on. The SIGLEC6 receptor binds sialyl-TN glycans and leptin. Placental expression SIGLEC6 is upregulated in preeclampsia.

Pyridoxal phosphate phosphatase PHOSPHO2, orphan 2 (PHOSPHO2) is a member of the haloacid dehalogenase (HAD) superfamily. Phosphatase has an elevated activity toward phosphoethanolamine (PEA) and phosphocholine (PCho). PHOSPHO 1, a phosphoethanolamine/phosphocholine phosphatase, is upregulated in mineralizing cells and is believed to be implicated in the production of inorganic phosphate for bone mineralization. PHOSPHO2 is a recognized phosphatase sharing a 42% sequence identity with PHOSPHO1. PHOSPHO1 and PHOSPHO2 are especially similar, however surprisingly recombinant PHOSPHO2 hydrolyses phosphoethanolamine and phosphocholine comparatively inadequately.