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GTPase, IMAP Family Member 5 (GIMAP5) is a part of the GTP-binding superfamily and the immuno-associated nucleotide subfamily of nucleotide-binding proteins. GIMAP5 is an antiapoptotic protein which is required for mitochondrial integrity and T-cell survival. Polymorphisms in GIMAP5 are related with systemic lupus erythematosus. Read-through transcription can be found between GIMAP5 and the neighboring upstream GIMAP1 (GTPase, IMAP family member 1) gene. GIMAP5 also contributes to T-cell quiescence.

GIMAP6 is a member of the GTPases of immunity-associated proteins (GIMAP) family. GIMAP proteins contain GTP-binding and coiled-coil motifs, and may play roles in the regulation of cell survival. Decreased expression of this gene may play a role in non-small cell lung cancer. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene, which is found in a cluster with seven additional GIMAP genes on the long arm of chromosome 7.

GPN-loop GTPase 1 (GPN1) is a member of the GPN-loop GTPase family. GPN1 is a guanosine triphosphatase enzyme which has a role in DNA repair and may function in activation of transcription. Small GTPases, which share a biochemical mechanism, act as binary molecular switches and function in the cell is nucleocytoplasmic transport of both proteins and RNA. In addition, GPN1 establishs an interface between the RNA polymerase II enzyme and chaperone/scaffolding protein, proposing that it is essential to connect RNA polymerase II to regulators of protein complex formation. GPN1 may also be involved in nuclear localization of XPA.

Immunity-related GTPase family M protein (IRGM) is essential for clearance of severe protozoan and bacterial infections. IRGM belongs to the p47 immunity-related GTPase family. IRGM serves in innate immune response possibly via regulation of autophagy. IRGM regulates proinflammatory cytokine production and inhibit endotoxemia upon infection and also has a part in macrophages adhesion and motility. Polymorphisms which modify the natural expression of the IRGM gene are associated with a susceptibility to Crohn's disease and tuberculosis.

G3BP1 belongs to the heterogeneous nuclear RNA-binding proteins and is also an element of the Ras signal transduction pathway. G3BP1 is one of the DNA-unwinding enzymes that favors partially unwound 3'-tailed substrates and is also able to unwind partial RNA/DNA and RNA/RNA duplexes in an ATP-dependent fashion. G3BP1 binds specifically to the Ras-GTPase-activating protein by associating with its SH3 domain. In addition, G3BP1 cleaves exclusively between cytosine and adenine and cleaves MYC mRNA preferentially at the 3'-UTR.

RND3 is a small GTPase which is part of the Ras superfamily that controls the association of the actin cytoskeleton in reaction to extracellular growth factors. RND3 activity causes a decrease in stress fibers and an increase in cell migration, at least in part through regulation of the Rho-dependent kinase ROCK1. RND3 inhibits DNA-damage induced apoptosis and cell cycle arrest. RND3 binds GTP and is resistant to Rho-specific GTPase-activating proteins.

Inositol monophosphatase 3 (IMPAD1) belongs to the inositol monophosphatase family. IMPAD1 is restricted to the Golgi apparatus and catalyzes the hydrolysis of phosphoadenosine phosphate (PAP) to adenosine monophosphate (AMP). IMPAD1 gene mutations cause the GRAPP type chondrodysplasia with joint dislocations, and a pseudogene of the IMPAD1 gene is located on the long arm of chromosome 1.

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.

RND1 is a Rho-related GTPases that form a separate branch of the Rho family, since they are different in charge, size, and biochemical properties. RND1 is found in the activated GTP-bound form and performs as a negative regulator of actin assembly and of cell adhesion. RND1 assists in regulation of the organization of the actin cytoskeleton as a reaction to extracellular growth factors.

Inositol monophosphatase1 (IMPA1) is responsible for the provision of inositol essential for synthesis of phosphatidylinositol and polyphosphoinositides. IMPA1 has a central role in the phosphatidylinositol signaling pathway by catalyzing the hydrolysis of inositol monophosphates. IMPA1 has been recognized as the pharmacological target for lithium action in the brain. The IMPA1 enzyme has a magnesium-dependent phosphatase activity and is inhibited by therapeutic concentrations of lithium. Inhibition of inositol monophosphate hydroylosis and ensuing depletion of inositol for phosphatidylinositol synthesis may perhaps explain the anti-manic and anti-depressive effects of lithium administered to treat bipolar disorder.

Inositol Monophosphatase Domain Containing 1 or IMPAD1 is a protein, part of the inositol monophosphatase group of proteins. The protein is found in Golgi apparatus and enhances phosphoadenosine phosphate hydrolysis to adenosine monophosphate. When Mutation in the IMPAD1 gene occurs leads to GRAPP type chondrodysplasia and therefore joint dislocations. On long arm chromosome 1 a pseudogene can be found.

Inositol monophosphatase 3 (IMPAD1) belongs to the inositol monophosphatase family. IMPAD1 is restricted to the Golgi apparatus and catalyzes the hydrolysis of phosphoadenosine phosphate (PAP) to adenosine monophosphate (AMP). IMPAD1 gene mutations cause the GRAPP type chondrodysplasia with joint dislocations, and a pseudogene of the IMPAD1 gene is located on the long arm of chromosome 1.

IMPA2 is a member of the inositol monophosphatase family. IMPA2 catalyzes the dephosphoylration of inositol monophosphate and has a significant role in phosphatidylinositol signaling. IMPA2 can use the myo-inositol monophosphates, scylloinositol 1,4-diphosphate, glucose-1-phosphate, beta-glycerophosphate, and 2'-AMP as substrates. IMPA2 is a pharmacological target for lithium Li(+) action in brain. IMPA2 is considered to have a role in schizophrenia and bipolar disorder.

The somatomedins, or insulin-like growth factors (IGFs), comprise a family of peptides that play important roles in mammalian growth and development. IGF1 mediates many of the growth-promoting effects of growth hormone (GH; MIM 139250). Early studies showed that growth hormone did not directly stimulate the incorporation of sulfate into cartilage, but rather acted through a serum factor, termed 'sulfation factor,' which later became known as 'somatomedin' (Daughaday et al., 1972). Three main somatomedins have been characterized: somatomedin C (IGF1), somatomedin A (IGF2; MIM 147470), and somatomedin B (MIM 193190) (Rotwein, 1986; Rosenfeld, 2003).

ITPA enzyme catalyzes the pyrophosphohydrolysis of both ITP (inosine triphosphate) and dITP (deoxyinosine triphosphate) to IMP (inosine monophosphate) and diphosphate. IMP is exercised as a substrate for purine nucleotide pathways. IMP is phosphorylated to ITP, and ITPA mediates the concentration of ITP in the cell by changing ITP back to IMP. Defects in ITPA result in ITPA deficiency which is thought to be inherited and is characterized by an over-accumulation of ITP in erythocytes, leukocytes and fibroblasts.

PTP4A2 is part of a small class of the protein tyrosine phosphatase (PTP) family. PTP4A2 is localized to the early endosome that take part in a variety of cellular activities. PTP4A2 protein interacts with the beta-subunit of Rab geranylgeranyltransferase II (beta GGT II), therefore has a role as a regulator of GGT II activity. Overexpression of PTP4A2 in mammalian cells conferred a transformed phenotype, which suggested its role in tumorigenesis.

GADD45GIP1 is a nuclear protein which takes part in apoptosis control. GADD45GIP1 is expressed in several tissues, such as heart, thyroid, trachea, kidney, ovary, pancreas, testis and stomach and acts as a negative regulator of G1 to S phase cell cycle production by collaborating with GADD45 proteins to inhibit the activity of cyclin-dependent kinases.

GMDS is a member of the GDP-mannose 4,6-dehydratase family. GMDS uses NADP as a cofactor to catalyze the conversion of GDP-mannose to GDP-4-keto-6-deoxymannose. Defects in the gene encoding GMDS cause TRAIL (tumor necrosis factor-related apoptosis-inducing ligand)-induced apoptosis.

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.

Protein Tyrosine Phosphatase Type IVA Member 3 (PTP4A3) is a member of a small class of prenylated protein tyrosine phosphatases (PTPs) which remove phosphate modifications from tyrosine residues on proteins. PTP4A3 enhances cell proliferation, cell motility and invasive activity. PTP4A3 functions as a protein tyrosine phosphatase which stimulates progression from G1 into S phase during mitosis. PTP4A3 is mostly expressed in cardiomyocytes and skeletal muscle; it is also found in the pancreas.
PTP4A3 is always overexpressed in colon cancer metastasis. PTP4A3 is notably overexpressed in liver metastasis of colorectal cancer. High levels of PTP4A3 expression are linked to tumorigenesis and metastasis; therefore it is overexpressed in metastatic colorectal, ovarian, liver and skin cancers. PTP4A3 may be involved in the progression of cardiac hypertrophy by inhibiting intracellular calcium mobilization in response to angiotensin II. PTP4A3 is inhibited by sodium orthovanadate and peroxovanadium compounds.

GGCT is a member of the family of transferases, specifically the aminoacyltransferases. GGCT protein catalyzes the formation of 5-oxoproline from gamma-glutamyl dipeptides and takes an important part in glutathione homeostasis. GGCT induces release of cytochrome c from mitochondria with resultant induction of apoptosis.

GPT catalyzes the reversible transamination between alanine and 2-oxoglutarate to create pyruvate and glutamate. GPT has a crucial part in the intermediary metabolism of glucose and amino acids. GPT is broadly used as an indicator of liver reliability or hepatocellular destruction in clinical tests.

THTPA enzyme is part of the THTPase family. THTPA is localized to the cytoplasm and expressed at small quantities in a variety of tissues, including testis, uterus, prostate, bladder, lung and kidney. THTPA is a hydrolase that catalyzes the H2O-dependent hydrolysis of thiamine triphosphate (THTP) to thiamine diphosphate (THDP), the main form of thiamine within the cell. THTPA occurs as a monomer and is activated at an optimal pH of 8.5.

GMP synthase (GMPS) is involved in purine biosynthesis. GMPS, which is a homodimer, catalyzes the last step in the GMP synthesis pathway, specifically the ATP-dependent amination of XMP to GMP. GMPS is comprised of one GMP-binding domain and one glutamine amidotransferase type-1 domain through which it communicates its catalytic activity. GMPS is engaged in the de novo synthesis of nucleotides which are not only vital for DNA and RNA synthesis, but also supply GTP, which is involved in sevral cellular processes important for cell division. GMPS gene chromosomal translocations are linked with acute myeloid leukemias, suggesting a possible role for GMPS in carcinogenesis.