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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.

SH2D1A acts as an inhibitor of the signaling lymphocyte activation molecule (SLAM) self-association. The SH2D1A protein is expressed at a high level in the thymus and the lung, with a lower level of expression in the spleen and the liver. The SH2D1A protein contains an SH2 domain and a short tail. SH2D1A has a key role in the bidirectional stimulation of T and B cells. Defects in the SH2D1A gene cause the X-linked lymphoproliferative disease (XLPD), aka Duncan disease. The XLPD is distinguished by a rare congenital immunodeficiency following an EBV infection (Epstein-Barr virus).

NCS1 is part of the neuronal calcium sensor gene family, which encode calcium-binding proteins expressed primarily in neurons. NCS1 regulates G protein-coupled receptor phosphorylation in a calcium-dependent manner and can substitute for calmodulin. NCS1 is related with secretory granules and modulates synaptic transmission and synaptic plasticity. NCS1 regulates GRK1 and substitutes for calmodulin. NCS1 stimulates PI4KB kinase activity and participates in long-term synaptic plasticity through its interaction with PICK1. NCS1 takes part in neuron differentiation through inhibition of the activity of N-type voltage-gated calcium channel.

ARL1 is part of the ARL (ADP-ribosylation factor-like) family of proteins, which are structurally associated to ADP-ribosylation factors (ARFs). ARFs, described as activators of cholera toxin (CT) ADP-ribosyltransferase activity, control intracellular vesicular membrane trafficking, and stimulate a phospholipase D (PLD) isoform.
ARL1 is a weak stimulator of PLD and CT in a phospholipid dependent manner.
ARL1 is a GTP-binding protein that has low efficiency as allosteric activator of the cholera toxin catalytic subunit, an ADP-ribosyltransferase. ARL1 is involved in the Golgi apparatus.

Actin-related protein 2/3 complex subunit 3 (ARPC3) which Belongs to the ARPC3 family is one of 7 subunits of the human Arp2/3 protein complex. The Arp2/3 complex is involved in regulation of actin polymerization and together with an activating nucleation-promoting factor (NPF) mediates the formation of branched actin networks. ARPC3 which is localized to the cytoplasm and cytoskeleton, interacts with p20-ARC and takes part in the structural integrity of the protein complex.

Arylsulfatase G (ARSG) is a member of the sulfatase enzyme family. Sulfatases are enzymes which hydrolyze sulfate esters from sulfated steroids, carbohydrates, proteoglycans, and glycolipids. Sulfatases are involved in hormone biosynthesis, modulation of cell signaling, and degradation of macromolecules. The ARSG protein exhibits arylsulfatase activity at acidic pH, as is characteristic of lysosomal sulfatases. The Arylsulfatase G enzyme localizes in the lysosomes. ARSG is inhibited by phosphate, which forms a covalent bond with the active site 3-oxoalanine. Arylsulfatase G is widely expressed, having very low expression in the brain, lung, heart and skeletal muscle.

Deoxyuridine Triphosphatase (DUT) is a ubiquitous enzyme that functions in nucleotide metabolism. Deoxyuridine Triphosphatase, in the presence of magnesium ions, is responsible for hydrolyzing dUTP to dUMP and diphosphate. This reaction is imperative for keeping the intracellular dUTP concentration low so that uracil does not become incorporated into DNA. Extensive integration of uracil into DNA can eventually lead to cell death. This suggests that DUT is crucial for cell viability, further implying that it is a prospective target for anticancer therapy.

ATPase Transporting, Lysosomal V1 Subunit F (ATP6V1F) is a component of vacuolar ATPase (V-ATPase); it is a multi-subunit enzyme, which mediates acidification of eukaryotic intracellular organelles. V-ATPase dependent organelle acidification is required for such intracellular processes as protein sorting, zymogen activation, receptor-mediated endocytosis, and synaptic vesicle proton gradient generation. V-ATPase is comprised of a cytosolic V1 domain and a transmembrane V0 domain. The V1 domain contains 3 A and 3 B subunits, 2 G subunits as well as the C, D, E, F, and H subunits. The V1 domain has the ATP catalytic site. The V0 domain consists of 5 different subunits: a, c, c', c', and d.

Sorting nexin 3 (SNX3) belongs to the large family of hydrophilic proteins, which interact with various receptor types and are involved in intracellular trafficking. SNX3 interacts with phosphatidylinositol-3-phosphate, and is involved in protein trafficking. SNX3 comprises a distinct subgroup of nexins, which share less sequence similarity outside of the PX domain and have significantly different binding affinities for the tyrosine kinase receptors.

Beta-1,3-glucuronyltransferase 3 (B3GAT3) is involved in forming the linkage tetrasaccharide present in heparan sulfate and chondroitin sulfate. B3GAT3 has a part in the biosynthesis of l2/HNK-1 carbohydrate epitope on glycoproteins. B3GAT3 shows strict specificity for Gal-beta-1,3-Gal-beta-1,4-Xyl, exhibiting negligible incorporation into other galactoside substrates including Galbeta1-3Gal beta1-O-benzyl, Galbeta1-4GlcNAc and Galbeta1-4Glc.

Streptavidin is a tetrameric protein secreted by Streptomyces avidinii which binds firmly to biotin. Streptavidin is widely used in molecular biology through its unique high affinity for the vitamin biotin. The dissociation constant (Kd) of the biotin-streptavidin complex is about ~10-15 mol/L. The strong affinity recognition of biotin and biotinylated molecules has made streptavidin one of the most important components in diagnostics and laboratory kits. The streptavidin/biotin system has one of the biggest free energies of association of yet observed for noncovalent binding of a protein and small ligand in aqueous solution (K_assoc = 10**14). The complexes are also extremely stable over a wide range of temperature and pH.

Programmed cell death 1 ligand 2 (PDCD1LG2) which takes part in the costimulatory signal, is necessary for T-cell proliferation. PDCD1LG2 is also involved in IFNG production in a PDCD1-independent way. The interaction with PDCD1 inhibits T-cell proliferation by preventing cytokine production and cell cycle progression.

FBP1 is a gluconeogenesis regulatory protein which catalyzes the hydrolysis of fructose 1,6-bisphosphate to fructose 6-phosphate and inorganic phosphate. FBP1 deficiency is associated with hypoglycemia and metabolic acidosis. FBP1 regulates mouse endogenous glucose production. FBP1 coupled with phosphofructokinase (PFK) takes part in the metabolism of pancreatic islet cells.

6PGD is the second dehydrogenase in the pentose phosphate shunt. Pentose is neccesary for nucleic acid biosynthesis. The pentose phosphate cycle is a major source of NADPH 6PGD deficiency is usually asymptomatic, and the inheritance of this disorder is autosomal dominant. PGD deficiency raises the erythrocyte pyruvate kinase levels of activity and decreases glutathione synthetase, resulting in hemolysis.

G6PD is the rate-limiting enzyme of the pentose phosphate pathway, a metabolic pathway that supplies reducing energy to cells by maintaining the level of NADPH. G6PD converts glucose-6-phosphate into 6-phosphoglucono-?-lactone and at the same time produces NADPH. The NADPH maintains the level of glutathione in these cells that helps protect the red blood cells against oxidative damage. G6PD deficiency causes acute hemolytic anemia, neonatal jaundice or acute hemolysis. G6PD is a cytosolic enzyme encoded by an X-linked gene whose main function is to produce NADPH, a crucial electron donor in the defense against oxidizing agents and in reductive biosynthetic reactions. G6PD produces pentose sugars for nucleic acid synthesis and is a main producer of NADPH reducing power.

Polymerase (RNA) III (DNA directed) Polypeptide H(POLR3H) is a member of the eukaryotic RPB7/RPC8 RNA polymerase subunit family. POLR3H is DNA-dependent RNA polymerase which catalyzes the transcription of DNA into RNA utilizing the 4 ribonucleoside triphosphates as substrates. POLR3H has a central role in sensing and curbing infection by intracellular bacteria and DNA viruses. POLR3H functions as nuclear and cytosolic DNA sensor which is involved in innate immune response.

UBE2D1 is a member of the ubiquitin-conjugating enzyme family. Ubiquitination involves at least 3 classes of enzymes: ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s) and ubiquitin-protein ligases (E3s). UBE2D1 is strongly related to a stimulator of iron transport (SFT), and is up-regulated in hereditary hemochromatosis. In addition, UBE2D1 functions in the ubiquitination of the tumor-suppressor protein p53 and the hypoxia-inducible transcription factor HIF1alpha by interacting with the E1 ubiquitin-activating enzyme and the E3 ubiquitin-protein ligases.

Glucose-6-phosphate isomerase (GPI) is a part of the GPI family whose members encode multifunctional phosphoglucose isomerase proteins involved in energy pathways. GPI is a dimeric enzyme which catalyzes the reversible isomerization of glucose-6-phosphate and fructose-6-phosphate. Mammalian GPI also functions as a tumor-secreted cytokine and an angiogenic factor (AMF) which stimulates endothelial cell motility. In addition, GPI is a neurotrophic factor (Neuroleukin) for spinal and sensory neurons. GPI performs in different capacities inside and outside the cell. In the cytoplasm, GPI is involved in glycolysis and gluconeogenesis, while outside the cell it acts as a neurotrophic factor for spinal and sensory neurons.
Defects in the GPI gene cause the nonspherocytic hemolytic anemia and a severe enzyme deficiency can be linked to hydrops fetalis, immediate neonatal death and neurological impairment.

Human Phosphoserine phosphatase (hPSP) is an important enzyme in the phosphorylated pathway of serine biosynthesis, which contributes a major portion of the endogenous L-serine. Similar to known L-3-phosphoserine phosphatases, it catalyzed the Mg2+-dependent hydrolysis of L-phosphoserine and an exchange reaction between L-serine and L-phosphoserine. Recently, its complex structures reveal that the open-closed environmental change of the active site, generated -helical bundle domain, is important to substrate by local rearrangement of the recognition and hydrolysis.

Uridine 5'-monophosphate synthase (UMPS), is a bifunctional enzyme that catalyzes the ultimate two steps of the de novo pyrimidine biosynthetic pathway. UMPS in eukaryotes links the orotate phosphoribosyltransferase and the orotidine-5’-monophosphate (OMP) decarboxylase activities into a single protein. The harmony of these 2 enzymes is assumed to be stabilized the catalytic centers as a result of the low molar concentration of the protein in mammalian cells.mutations in this gene are the reason of inherited orotic aciduria disease.

Glycogenin-1 (GYG1) is an enzyme involved in glycogen biosynthesis. GYG1 is the chief enzyme involved in glycogen polymerisation. Glycogenin-1 is vital for the function of self-glucosylates, using an inter-subunit mechanism, to form an oligosaccharide primer which acts as substrate for glycogen synthase. In addition, GYG1 has a role in regulating glycogen metabolism and the achievement of maximal glycogen levels in skeletal muscle. GYG1 mRNA and protein content and activity increase in the muscle during recovery from prolonged and exhaustive exercise. GYG1 is inactivated with glycogen catabolism which concurs with an increase in glycogenin gene expression as exercise and glycogenolysis advance. Glycogenin will remain covalently attached to the reducing end of the glycogen molecule.

CPPED1 which is a part of the metallophosphoesterase superfamily takes part in glucose uptake by adipocytes. CPPED1 binds two divalent metal cations and is transactivated by the great envelope protein of the hepatitis B virus.

RANKL binds to tnfrsf11b/opg and to tnfrsf11a/rank. Osteoclast differentiation and activation factor. Augments the ability of dendritic cells to stimulate naive t-cell proliferation. May be an important regulator of interactions between t-cells and dendritic cells and may play a role in the regulation of the t-cell-dependent immune response. sRANKL may also play an important role in enhanced bone-resorption in humoral hypercalcemia of malignancy.

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.