Search results

Serine/threonine-protein kinase 16 (STK16) is a membrane-associated protein kinase which phosphorylates on serine and threonine residues. STK16 is involved in secretory vesicle trafficking or intracellular signaling. Furthermore, the STK16 protein may have a role in regulating stromal-epithelial interactions which occur during ductal morphogenesis in the mammary gland. STK16 can autophosphorylate on Tyr residue; it is however unclear whether STK16 has tyrosine-protein kinase toward other proteins. STK16 may also be involved in TGF-beta signaling.

The protein kinase A holoenzyme is a heterotetramer composed of two types of subunits: Catalytic and Regulatory. The Catalyticsubunit contains the enzyme's active site. It also contains a domain that binds ATP and a domain that binds the regulatory subunit. The Regulatory subunit consists oftwo molecules which bind one another in an anti-parallel orientation to form a homodimer; for type I subunits- this binding is covalent via disulfide bonds. This subunit also has has two domains that bind cyclic AMP, a domain that interacts with a catalytic subunit, and an "auto-inhibitory" domain that serves as a substrate or pseudosubstrate for the catalytic subunit. Regulatory subunits may also have biologic activity distinct from their role in modulating catalytic subunit activity. Regulatory subunits exist in two major forms, RI and RII, with each form having two subtypes designated alpha and beta. Each of the four isotypes of the regulatory subunit is encoded by a different gene. In addition, three isotypes of the catalytic subunit have been identified (alpha, beta and gamma). The different isotypes tend to have different distributions within cells and among tissues. Type I enzymes inhabit cytoplasmic, soluble fractions of the cell, whereas type II enzymes tend to associate with cellular membranes.

Pyruvate kinase is a key enzyme in the glycolytic pathway. The M2 isoenzyme of pyruvate kinase is specifically expressed at high levels in tumor cells, and can be measured in plasma of patients with advanced breast cancer. The marker is useful for measuring disease activity, sensitivity to chemotherapy and recurrence.

UMP-CMP kinase and deoxycytidylate kinase (CMPK1) is an enzyme which catalyzes the phosphoryl transfer from ATP to UMP, CMP and dCMP. This enzymatic reaction brings about the formation of ADP and the corresponding nucleoside diphosphate that are necessary for cellular nucleic acid synthesis. In addition, CMPK1 has a significant role in the activation of pyrimidine analogs, which are clinically useful anti-cancer and anti-viral drugs.

TSSK2 is a testis-specific serine/threonine-protein kinase required during spermatid development which phosphorylates TSKS at 'Ser-288' and SPAG16. TSSK2 takes part in the late stages of spermatogenesis, during the reconstruction of the cytoplasm. During spermatogenesis, TSSK2 is necessary for the transformation of a ring-shaped structure around the base of the flagellum originating from the chromatoid body.

5'-AMP-activated protein kinase subunit beta-1 (PRKAB1) hinders protein, carbohydrate and lipid biosynthesis, in addition to cell growth and proliferation. AMPK is a heterotrimer comprised of an alpha catalytic subunit, and non-catalytic beta and gamma subunits. AMPK acts via direct phosphorylation of metabolic enzymes, and longer-term effects by phosphorylation of transcription regulators. PRKAB1 is a regulator of cellular polarity by remodeling the actin cytoskeleton; most likely by indirectly activating myosin. Beta non-catalytic subunit acts as a scaffold on which the AMPK complex compiles, through its C-terminus that joins alpha (PRKAA1 or PRKAA2) and gamma subunits (PRKAG1, PRKAG2 or PRKAG3).

Pyruvate kinase is a key enzyme in the glycolytic pathway. The M2 isoenzyme of pyruvate kinase is specifically expressed at high levels in tumor cells, and can be measured in plasma of patients with advanced breast cancer. The marker is useful for measuring disease activity, sensitivity to chemotherapy and recurrence.

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.

cAMP-dependent protein kinase catalytic subunit alpha isoform Calpha1 (PRKACA) belongs to the Ser/Thr protein kinase family. PRKACA is responsible for phosphorylating other proteins and substrates, changing their activity. The PRKACA protein is a member of the AGC kinase family, and contributes to the regulation of cellular processes which include glucose metabolism, cell division, and contextual memory.

Serum-and glucocorticoid-regulated kinase (SGK1) is a serine/threonine protein kinase and a member of the “AGC” subfamily, which includes protein kinases A, G, and C. The SGK1 protein has an imperative role in activating specific potassium, sodium and chloride channels, suggesting a participation in the regulation of processes such as cell survival, neuronal excitability, and renal sodium excretion. SGK1 is activated in vitro by PDK-1 (3-phosphoinositide-dependent protein kinase-1) and in vivo in reaction to signals which activate phosphatidylinositol (PI) 3-kinase.

Inositol-tetrakisphosphate 1-kinase (ITPK1) is a 414 amino acid monomer which is a member of the ITPK1 family and exists as 2 alternatively spliced isoforms. ITPK1 highest levels are found in the brain, followed by the heart, skeletal muscle, kidney, pancreas, liver, placenta and lung. ITPK1 is comprised of one ATP-grasp domain and has been shown to phosphorylate various inositol polyphosphates and modify TNFa induced apoptosis.

PDXK converts vitamin B6 to Pyridoxal-5-phosphate (PLP), which is a vital cofactor in the intermediate metabolism of amino acids and neurotransmitters. PDXK is cytoplasmic and probably acts as a homodimer. The biological validity of the alternatively spliced transcript variants has not been determined.

PAK4 is part of the group B family of p21-activated kinases (PAK). It's known as an effector protein for cell division cycle 42(Cdc42) and protein that plays an important role in regulating cytoskeletal organization and cell morphology. PAK4 expression is eminent in many cancer cell lines, and is involved in tumorigenesis. PAK proteins are significant effectors that associate Rho GTPases to cytoskeleton reorganization and nuclear signaling. PAK proteins are targets for the small GTP binding proteins Cdc42 and Rac and have been implicated in a wide range of biological activities. PAK4 cooperates specifically with the GTP-bound form of Cdc42Hs and weakly activates the JNK family of MAP kinases. PAK4 is a mediator of filopodia formation and is involved in the reorganization of the actin cytoskeleton. PAK4 activates the JNK pathway. PAK4 phosphorylates and inactivates the protein phosphatase SSH1, leading to increased inhibitory phosphorylation of the actin binding/depolymerizing factor cofilin. Decreased cofilin activity may lead to stabilization of actin filaments.

Janus Kinase 2 (JAK2) is a protein tyrosine kinase which takes part in a specific subset of cytokine receptor signaling pathways such as cell growth, development, differentiation or histone modifications. JAK2 is linked with the prolactin receptor and is necessary for responses to gamma IFN. Mice which do not express an active protein for JAK2 show embryonic lethality associated with the absence of definitive erythropoiesis.

Thymidine Kinase 1 (TK1) is a phosphotransferase (a kinase): 2'-deoxythymidine kinase, ATP-thymidine 5'-phosphotransferase. TK1 is present in 2 forms in mammalian cells, TK1 and TK2. Thymidine kinases hold a main function in the synthesis of DNA and thus in cell division, as they are part of the distinctive reaction chain to introduce deoxythymidine (present in the body fluids as a result of degradation of DNA from food and from dead cells) into the DNA. Thymidine kinase is necessary for the action of many antiviral drugs. Thymidine kinase is used to select hybridoma cell lines in production of monoclonal antibodies.

MOB Kinase Activator 1B (MOB1B) is similar to the yeast Mob1 protein. Yeast Mob1 binds Mps1p, which is a protein kinase vital for spindle pole body duplication and mitotic checkpoint regulation.

C-Src Tyrosine Kinase, also known as CSK, regulates cell growth, migration, differentiation, and immune response. CSK Phosphorylates tyrosine residues located in the C-terminal tails of Src-family kinases. CSK is a protein coding gene which suppresses signaling by several surface receptors. Among CSK's related pathways are PI-3K cascade and Signaling by FGFR.

MOB3B is similar to yeast Mob1 protein which binds Mps1p, a protein kinase vital for spindle pole body duplication and mitotic checkpoint regulation. MOB3B is situated on the opposite strand as the INF kappa precursor (IFNK) gene.

Nucleoside diphosphate kinase (Ndk) is an enzyme which catalyzes the exchange of phosphate groups between different nucleoside diphosphates. Ndk’s activity sustains equilibrium between the concentrations of various nucleoside triphosphates for example, when GTP is produced in the citric acid (Krebs) cycle is converted to ATP. Ndk has a key role in the synthesis of nucleoside triphosphates other than ATP.

MVK is a member of the GHMP kinase family. Mevalonate is a vital mediator, and MVK an important early enzyme, in isoprenoid and sterol synthesis. MVK deficiency can result in gene mutation associated with Mevalonic aciduria, an illness which causes psychomotor retardation, failure to thrive hepatosplenomegaly, anemia and frequent febrile crises. Mutations in this gene also cause hyperimmunoglobulinaemia D and sporadic fever syndrome, in which the person suffers from recurrent episodes of fever related with lymphadenopathy, skin rash, gastrointestinal dismay and arthralgia.

Phosphomevalonate kinase (PMVK) is a cytosolic enzyme. PMVK is expressed highly in the heart, liver, skeletal muscle, kidney and pancreas and slightly lower in the brain, placenta, and lung. PMVK catalyzes the conversion of mevalonate 5-phosphate into mevalonate 5-diphosphate in the fifth reaction of the cholesterol biosynthetic pathway. Induced by sterol, PMVK participates in isopentenyl diphosphate biosynthesis via the mevalonate pathway.

PINK1 is a serine/threonine protein kinase which is found in the mitochondria. PINK1 shields cells from stress-induced mitochondrial dysfunction. Mutations results in one form of autosomal recessive early-onset Parkinson disease.

Dual-Specificity Tyrosine-(Y)-Phosphorylation Regulated 1A (DYRK1A) belongs to the dual-specificity tyrosine phosphorylation-regulated kinase (DYRK) family. DYRK1A includes a nuclear targeting signal sequence, a leucine zipper motif and a protein kinase domain. DYRK1A catalyzes its autophosphorylation on serine/threonine and tyrosine residues and takes part in a signaling pathway regulating cell proliferation. DYRK1A has a substrate preference for proline at position P+1 and arginine at position P-3.