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Dual Specificity Phosphatase 6, also known as DUSP6 belongs to the dual specificity protein phosphatase subfamily. DUSP6 is a Protein coding gene which inactivates MAP kinases. Various members of the family of dual specificity phosphatases show diverse tissue distribution, subcellular localization, and different modes of inducibility of their expression by extracellular stimuli.

Hexokinases phosphorylate glucose to produce glucose-6-phosphate, thus committing glucose to the glycolytic pathway. Hexokinase 2 is the predominant form found in skeletal muscle. It localizes to the outer membrane of mitochondria. Expression of this gene is insulin-responsive, and studies in rat suggest that it is involved in the increased rate of glycolysis seen in rapidly growing cancer cells.

ErbB3, also called Her3 (human epidermal growth factor receptor 3), is a type I membrane glycoprotein that is a member of the ErbB family of tyrosine kinase receptors. ErbB family members serve as receptors for the epidermal growth factor (EGF) family of growth factors. Among ErbB family members, ErbB3 is unique in that it contains a defective kinase domain. ErbB3 is expressed in keratinocytes, melanocytes, skeletal muscle cells, embryonic myoblasts and Schwann cells. Monomeric ErbB3 serves as a low affinity receptor for the heregulins (HRG). ErbB3 can induce specific antibody production in vivo, hence to inhibit tumor cell growth. ErbB-3 can be used to treat early, medium and advanced or post-operative breast cancer with over-expression of ErbB2. According to its mechanism of action, ErbB3 is classified as a therapeutic for cancer.

PPP3CA (aka Calcineurin A) is a major soluble calmodulin binding protein in the brain and a Ca2+/calmodulin dependent serine/threonine protein phosphatase, with a relatively limited substrate specificity. PPP3CA activates the T cells of the immune system and can be blocked by drugs. PPP3CA activates NFATc (a transcription factor) by dephosphorylating it. The activated NFATc is subsequently translocated into the nucleus, where it upregulates the expression of interleukin 2.

Adenylate kinase isoenzyme 5 (AK5) belongs to the adenylate kinase family, which is involved in regulating the adenine nucleotide composition within a cell by catalyzing the reversible transfer of phosphate groups among adenine nucleotides. AK5 is related to the UMP/CMP kinase of several species. AK5 is located in the cytosol and expressed exclusively in the brain.

Staphylokinase (SAK) is a 136-amino acidenzymefrom Staphylococcus aureus. It is positively regulated by the "agr" gene regulator. It activates plasminogen, which in turn can degrade various host proteins during infection.

Endothelial cells express three different vascular endothelial growth factor (VEGF) receptors, belonging to the family of receptor tyrosine kinases (RTKs). They are named VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), VEGFR-3 (Flt-4). Their expression is almost exclusively restricted to endothelial cells, but VEGFR-1 can also be found on monocytes. All VEGF-receptors have seven immunoglobulin-like extracellular domains, a single transmembrane region and an intracellular split tyrosine kinase domain. VEGFR-2 has a lower affinity for VEGF than the Flt-1 receptor, but a higher signaling activity. Mitogenic activity in endothelial cells is mainly mediated by VEGFR-2 leading to their proliferation.
Differential splicing of the flt-1 gene leads to the formation of a secreted, soluble variant of VEGFR-1 (sVEGFR-1). No naturally occuring, secreted forms of VEGFR-2 have so far been reported. The binding of VEGF165 to VEGFR-2 is dependent on heparin.

Kallikrein-3 or KLK3 is a serine proteases subgroup, enzymes can cleave peptide bonds. KLK3 is found in the prostate and may be hold accountable to the regulation of semen liquefaction via seminogelin hydrolysis. The protein is expressed in low concentrations in men with healthy prostates serum. When elevated quantities are found it may show prostate cancer or different prostate disorders such as prostatitis and benign prostatic hyperplasia.

Fructosamine 3 Kinase (FN3K) catalyzes the phosphorylation of fructosamines which may result in deglycation, the non-enzymatic reaction of glucose with primary amines followed by Amadori re-arrangement. Phosphorylation of fructosamines instigates metabolism of the modified amine and brings about the de-glycation of fructoselysine and of glycated proteins. A high concentration of glucose may affect non-enzymatic oxidation of proteins by reaction of glucose and lysine residues (glycation). Fructosamines, the proteins altered in this way, are less active or functional.

DUSP10 is a member of the protein-tyrosine phosphatase family. DUSPs inactivate their target kinases by dephosphorylating both the phosphoserine/threonine and phosphotyrosine residuesb and negatively regulate members of the MAPK superfamily which is linked with cellular proliferation and differentiation. DUSP10 interacts with MAPK14 and MAPK8. DUSP10 blocks in mammalian cells the enzymatic activation of MAP kinases with the selectivity p38 approximately JNK/SAPK >> ERK.

CRK belongs to the signaling adapter protein family which binds to several tyrosine-phosphorylated proteins. CRK is involved in many cellular processes such as apoptosis, proliferation, and differentiation. CRK has a modular domain architecture consisting of an SH2 followed by two SH3 domains (src-homology domains). The N-terminal SH2 domain of the CRK protein functions as a positive regulator of transformation whereas the C-terminal SH3 domain functions as a negative regulator of transformation.

Calcipressin-3 (RCAN3) takes part in central nervous system development. RCAN3 inhibits calcineurin-dependent transcriptional responses by binding to the catalytic domain of calcineurin A. Overexpression of calcipressin-3 results in inhibition of calcineurin activity towards the nuclear factor of activated T-cells (NFAT) transcription factors and also downregulates NFAT-dependent cytokine gene expression in activated Jurkat T-cells. Highest expression takes place s in heart, skeletal muscle kidney, liver and peripheral blood leukocytes.

Tachykinin-1 (TAC1) belongs to the tachykinin peptide hormone family. TAC1 are a family of peptides which have similar biologic activities and share a common C-terminal sequence, phe-X-gly-leu-met-NH2, however they have distinct N-terminal sequences that convey receptor specificities. TAC1 is assumed to act as neurotransmitters which interact with nerve receptors and smooth muscle cells. TAC1 induces behavioral responses and serves as vasodilators and secretagogues.

Serine/Threonine-protein phosphatase PP1-alpha catalytic subunit (PPP1CA) is crucial for cell division, and participates in the regulation of glycogen metabolism, muscle contractility and protein synthesis. The PPP1CA protein may have a significant role in dephosphorylating substrates such as the postsynaptic density-associated Ca2+/calmodulin dependent protein kinase II.

PFKM is a regulatory glycolytic enzyme that converts fructose 6-phosphate and ATP into fructose 1,6-bisphosphate (through PFK-1), fructose 2,6-bisphosphate (through PFK-2) and ADP. Three phosphofructokinase isozymes exist in humans: muscle, liver and platelet. Mutations in PFKM gene have been related with glycogen storage disease type VII, also identified as Tarui disease.

Calcium-binding protein 7 (CABP7) contains 2 EF-hand domains. CABP7 negatively regulates Golgi-to-plasma membrane trafficking by interacting with PI4KB and inhibiting its activity. The CaBP family of EF-hand containing small Ca (2+)-binding proteins has lately emerged as significant regulators of multiple targets essential to normal neuronal function in the mammalian central nervous system.

Dickkopf-related protein 1 (DKK1) antagonizes canonical Wnt signaling by inhibiting LRP5/6 interaction with Wnt and by creating a ternary complex with the transmembrane protein KREMEN which promotes internalization of LRP5/6. DKKs have a significant role in vertebrate development, where they locally inhibit Wnt controlled processes for instance antero-posterior axial patterning, limb development, somitogenesis and eye formation. Furthermore, Dkks are involved in bone formation and bone disease, cancer and Alzheimer disease in Adults.

Hexokinases phosphorylate glucose to produce glucose-6-phosphate, thus committing glucose to the glycolytic pathway. HK3 encodes hexokinase 3. Similar to hexokinases 1 and 2, this allosteric enzyme is inhibited by its product glucose-6-phosphate. Hexokinase3 lacks the hydrophobic N-terminal sequence critical for targeting to mitochondria. Hexpkinase3 may have anabolic functions, providing H6P for glycogen or lipid synthesis.

Calbindins are Ca-binding proteins belonging to the troponin C superfamily. CALB28K/Calbindin1/CALB1 (D28K/Spot35 protein or cholecalcin, rat 261 aa; mouse 261 aa; human 261-aa, chromosome 8q21.3-q22.1) was originally described as 27-kDA induced by vitamin D in the duodenum of chicken. In mammals, it is expressed in the kidney, pancreatic islets, and brain. In brain, its synthesis is independent of vitamin D. CABP28K contains 4 active and 2 inactive EF-hand Ca-binding domains. The gene for CABP28K is clustered in the same region as carbonic anhydrase. The neurons in the brains of patients with Huntington disease are CAB28K depleted. There are two types of CaBPs: the "trigger"- and the "buffer"-CaBPs. The conformation of "trigger" type CaBPs changes upon Ca2+ binding and exposes regions on protein that interact with target molecules, thus altering their activity. The buffer-type CABP are thought to control the intracellular calcium concentration. Calbindin D-28K is found predominantly in subpopulations of central and peripheral nervous system neurons, and in certain epithelial cells involved in Ca2+ transport such as distal tubular cells and cortical collecting tubules of the kidney, and in enteric neuroendocrine cells.

AK1 is a small ubiquitous enzyme which is essential for maintenance and cell growth. It is involved in the regulation of adenine nucleotide composition within a cell by catalyzing the reversible transfer of the terminal phosphate group between ATP and AMP. The AK1 protein is found in the cytosol of skeletal muscle, brain and erythrocytes. Defects in the AK1 gene are the cause of a form of hemolytic anemia.

The PI3Kb isoform can be activated by insulin via the insulin receptor to initiate a cascade of events that control cell growth and metabolism. The activation of
PI3Kb is mediated by the p85 regulatory subunit binding to tyrosine phosphorylated insulin receptor substrate (IRS) proteins (e.g. IRS-1 and IRS-2).
It was also shown that PI3Kb is involved in apoptosis in human colon carcinoma cells. Injection of neutralizing antibodies specific to p110b in WiDr,
HCT116 and CO 115 adenocarcinoma cells inhibited de novo DNA synthesis.
PI3Kb is the major PI3K isoform required for apoptotic cell and Fc-g receptor mediated phagocytosis shown for primary mouse macrophages and the Jurkat human leukemia T cell line.
It was shown by several research groups that the catalytic subunit of PI3Kb can be activated by Gbg subunits of G-protein coupled receptors.

S100G (calbindin D9K) is a vitamin D-dependent calcium-binding protein. S100G, which is a cytosolic protein, is a member of a family of calcium-binding proteins that includes calmodulin, parvalbumin, troponin C, and S100 protein. In the intestine, S100G is vitamin D-dependent and its expression correlates with calcium transport activity. S100G may increase Ca2+ absorption by buffering Ca2+ in the cytoplasm and increase ATP-dependent Ca2+ transport in duodenal basolateral membrane vesicles.

Cyclin-dependent kinase inhibitors (CDKIs) are proteins that bind to and inhibit the activity of CDKs. Two major classes of CDK inhibitors have been identified. The p16 family (p15, p16, p18 and p19) binds to and inhibits the activities of CDK4 and CDK6. The p21 family (p21, p27, p28 and p57) can bind to broad range of CDK-cyclin complexes and inhibit their activities. CDKIs are capable of suppressing growth, and several lines of evidence strongly suggest that at least some CDKIs may be tumor suppressor proteins.