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tRNA 2'-phosphotransferase 1 (TRPT1) is a member of the KptA/TPT1 family. TRPT1 catalyzes the last step of tRNA splicing, the transfer of the splice junction 2'-phosphate from ligated tRNA to NAD to produce ADP-ribose 1''-2'' cyclic phosphate. TRPT1 is broadly expressed; it is weakly or not expressed in the lung, spleen, small intestine and peripheral blood leukocytes.

Methionine sulfoxide reductase B3 (MSRB3) is a member of the methionine sulfoxide reductases (MSR) family proteins. MSRB3 catalyzes the reduction of methionine sulfoxide to methionine. The MSRB3 enzyme acts as a monomer and requires zinc as a cofactor. MSRs are thought to defend against reactive oxygen species-induced oxidative damage in various organs, including the most environmentally exposed organ, the human skin. MSRB3 has a vital role in cold tolerance by eliminating MetO and ROS which accumulate at the ER during cold acclimation.

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 alteration of proteins with ubiquitin is a vital cellular mechanism for targeting atypical or short-lived proteins for degradation. Ubiquitination involves noT less than three classes of enzymes: ubiquitin-activating enzymes, or E1s, ubiquitin-conjugating enzymes, or E2s, and ubiquitin-protein ligases, or E3s. UBE2A is part of the E2 ubiquitin-conjugating enzyme family. UBE2A is necessary for post-replicative DNA damage repair. UBE2A catalyzes the covalent attachment of ubiquitin to other proteins. UBE2A is necessary for postreplication repair of UV-damaged DNA.

BPNT1 belongs to the magnesium-dependent, lithium-sensitive phosphomono-esterase superfamily. BPNT1 catalyzes the conversion of PAPS (adenosine 3'-phosphate 5' phosphosulfate) to APS (adenosine 5'-phosphosulfate) and the conversion of PAP (3'(2')-phosphoadenosine 5' phosphate) to AMP (adenosine 5'-phosphate) using magnesium as a cofactor. BPNT1 is expressed everywhere but at maximum levels in brain and kidney. BPNT1 is potently inhibited by lithium, a drug used for the treatment of manic depression and bipolar affective disorder, which suggests that BPNT1 has a possible role in the etiology of mood disorders.

Tripartite Motif Containing 33 (TRIM33) belongs to the tripartite motif family. This motif includes 3 zinc-binding domains, a RING, a B-box type 1 and a B-box type 2, and a coiled-coil region. TRIM33 is assumed to be a transcriptional corepressor. TRIM33 functions as an E3 ubiquitin-protein ligase. TRIM33 also promotes SMAD4 ubiquitination, nuclear exclusion and degradation via the ubiquitin proteasome pathway. In addition, TRIM33 inhibits the transcriptional response to TGF-beta/BMP signaling cascade. Furthermore, TRIM33 has a role in the control of cell proliferation.

GARS is an (alpha)2 dimer which is a member of the class II family of tRNA synthetases. GARS is a glycyl-tRNA synthetase, one of the aminoacyl-tRNA synthetases which charge tRNAs with their cognate amino acids. GARS catalyzes the attachment of glycine to tRNA(Gly). In addition, GARS is able to produce diadenosine tetraphosphate (Ap4A), which is a universal pleiotropic signaling molecule required for cell regulation pathways, by direct condensation of two ATPs. GARS has been demonstrated to be a target of autoantibodies in the human autoimmune diseases, polymyositis or dermatomyositis.

GlsA1 is a member of the great superfamily of serine-dependent beta-lactamases and penicillin-binding proteins which exist almost in every bacteria and eukaryotes and catalyze the hydrolytic deamidation of l-glutamine to l-glutamate and free NH4+.

FBL is a significant small nucleolar protein in eukaryotes, which has an essential role in pre-rRNA processing during ribosomal biogenesis. Fibrillarin is a component of several ribonucleoproteins including a nucleolar small nuclear ribonucleoprotein (SnRNP) and one of the two classes of small nucleolar ribonucleoproteins (snoRNPs). Fibrillarin contains an N-terminal repetitive domain which is rich in glycine and arginine residues, like fibrillarins in other species. Fibrillarin’s central region is similar to an RNA-binding domain and contains an RNP consensus sequence. FBL is linked to the U3, U8, and U13 small nuclear RNAs and is positioned in the dense fibrillar component (DFC) of the nucleolus. Antisera from roughly 8% of humans with the autoimmune disease scleroderma recognize fibrillarin.

NEDD8-activating enzyme E1 catalytic subunit (UBA3) is the catalytic subunit of the dimeric UBA3-NAE1 E1 enzyme, which belongs to the E1 ubiquitin-activating enzyme family. E1 activates NEDD8 by initially adenylating its C-terminal glycine residue with ATP, afterwards linking this residue to the side chain of the catalytic cysteine, generating a NEDD8-UBA3 thioester and free AMP. E1 at last transfers NEDD8 to the catalytic cysteine of UBE2M. The UBA3 enzyme connects with AppBp1, an amyloid beta precursor protein binding protein, to form a heterodimer, and at that point the enzyme complex activates NEDD8, a ubiquitin-like protein, which controls cell division, signaling and embryogenesis.

UBE2V2 comprises a distinct subfamily within the E2 protein family. They have sequence similarity to other ubiquitin-conjugating enzymes however require the conserved cysteine residue that is vital for the catalytic activity of E2s. UBE2V2 shares homology with ubiquitin-conjugating enzyme E2 variant 1 and yeast MMS2 gene product. UBE2V2 participates in the differentiation of monocytes and enterocytes.

Human Ubquitin Conjugating Enzyme 9 (Ubc9) is a member of the E2 family and is specific for the conjugation of SUMO to a variety of target proteins. SUMO conjugation to target proteins is mediated by a different, but analogous, pathway to ubiquitinylation. This E2 is unusual in that it interacts directly with protein substrates that are modified by sumolyation, and may play a role in substrate recognition. Ubc9 can mediate the conjugation of SUMO-1 to a variety of proteins including RanGAP1, I?B?, and PML without the requirement of an E3 ligase.

STK17A belongs to the DAP kinase-associated apoptosis-inducing protein kinase family and encodes an autophosphorylated nuclear protein with a protein kinase domain. STK17A acts as a positive regulator of apoptosis. STK17A is greatly expressed in the placenta with lower levels in the heart, lung, skeletal muscle, kidney and pancreas.

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.

Glutathione S-transferase A4 (GSTA4) is a member of the GST superfamily. The GSTA4 enzyme is involved in cellular defense against toxic, carcinogenic, and pharmacologically active electrophilic compounds. GSTA4 shows an especially high activity with reactive carbonyl compounds such as alk-2-enals. GSTA4 is extremely effective in catalyzing the conjugate addition of reduced glutathione to 4-hydroxynonenal, which is an important product of peroxidative degradation of arachidonic acid and a frequently used biomarker for oxidative damage in tissue. The GSTA4 enzyme is expressed at a high level in the brain, placenta, and skeletal muscle and much lower in the lung and liver.

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.

PTGES3 takes part as a cochaperone and is involved in signal transduction.
PTGES3 is a molecular chaperone that localizes to genomic response elements in a hormone-dependent manner and disrupts receptor-mediated transcriptional activation, by promoting disassembly of transcriptional regulatory complexess. PTGES3 is necessary for appropriate functioning of the glucocorticoid and other steroid receptors.
PTGES3 localizes to genomic response elements in a hormone-dependent method and disrupts receptor-mediated transcriptional activation, by promoting disassembly of transcriptional regulatory complexes.

Tryptase alpha/beta-1 (TPSAB1) is a tryptase which is the key neutral protease present in mast cells and is discharged upon the coupled activation-degranulation response of this cell type. TPSAB1 is enzymatically active only as a heparin-stabilized tetramer, and is resistant to all known endogenous proteinase inhibitors. TPSAB1 is implicated as a mediator in the pathogenesis of asthma and other allergic and inflammatory disorders.

Elastase-2 (ELANE) is a serine protease that belongs to the chymotrypsin family. ELANE breaks down elastin, an elastic fiber together with collagen and controls the mechanical properties of connective tissue. The neutrophil form breaks down the Outer membrane protein A (OmpA) of E. coli and other Gram-negative bacteria. ELANEis inhibited by the acute-phase protein alpha 1-antitrypsin (A1AT), which binds almost irreversibly to the active site of elastase and trypsin.A1AT is usually secreted by the liver cells into the serum. A1AD leads to uninhibited destruction of elastic fiber by elastase.

Ribonuclease H2 subunit A (RNASEH2A) is a member of the RNase HII family and eukaryotic subfamily. RNASEH2A Plays a part in DNA replication, probably by mediating the removal of lagging-strand Okazaki fragment RNA primers throughout DNA replication. RNASEH2A catalyzes the endonucleolytic cleavage of RNA to a 5’-phosphomonoester and is capable to bind magnesium or manganese as cofactors. Aicardi-Goutieres syndrome type 4 (AGS4) caused by defects in RNASEH2A.

ACO1 has a part in an iron sensor. ACO1 catalyzes the stereo-specific isomerization of citrate to isocitrate via cis-aconitate in the tricarboxylic acid cycle, a non-redox-active process.

Ubiquitin-conjugating enzyme E2S (UBE2S) belongs to the ubiquitin-conjugating enzyme family. UBE2S is able to form a thiol ester linkage with ubiquitin in a ubiquitin activating enzyme-dependent manner, a typical property of ubiquitin carrier proteins. UBE2S catalyzes the covalent attachment of ubiquitin to other proteins. UBE2S acts as a crucial factor of the anaphase promoting complex/cyclosome (APC/C), which is a cell cycle-regulated ubiquitin ligase that controls progression through mitosis. UBE2S acts by purposely elongating 'Lys-11'-linked polyubiquitin chains initiated by the E2 enzyme UBE2C/UBCH10 on APC/C substrates, augmenting the degradation of APC/C substrates by the proteasome and promoting mitotic exit. UBE2S also acts by elongating ubiquitin chains initiated by the E2 enzyme UBE2D1/UBCH5 in vitro; it is nevertheless uncertain whether UBE2D1/UBCH5 acts as an E2 enzyme for the APC/C in vivo. UBE2S is also involved in ubiquitination and consequent degradation of VHL, resulting in an accumulation of HIF1A.

AKR7A2 participates in the detoxification of aldehydes and ketones. AKR7A2 catalyzes the NADPH-dependent reduction of succinic semialdehyde to gamma-hydroxybutyrate. AKR7A2 is involved in producing the neuromodulator gamma-hydroxybutyrate (GHB). AKR7A2 has extensive substrate specificity. AKR7A2 shows NADPH-dependent aldehyde reductase activity towards 2-carboxybenzaldehyde, 2-nitrobenzaldehyde and pyridine-2-aldehyde (in vitro). AKR7A2 reduces 1,2-naphthoquinone and 9,10-phenanthrenequinone (in vitro). AKR7A2 reduces the dialdehyde protein-binding form of aflatoxin B1 (AFB1) to the non-binding AFB1 dialcohol. AKR7A2 takes part in protection of liver against the toxic and carcinogenic effects of AFB1, a potent hepatocarcinogen.