Protein Kinases

Ribokinase (RBKS) is a member of the pfkB family of carbohydrate kinases. Ribokinase phosphorylates ribose to form ribose-5-phosphate in the presence of ATP and magnesium as a first step in ribose metabolism.

MAP2K1 is a member of the dual specificity protein kinase family, which plays a role as a mitogen-activated protein (MAP) kinase kinase. MAP kinases, are recognized as extracellular signal-regulated kinases (ERKs), that act as an integration position for multiple biochemical signals. MEK1 is located upstream of MAP kinases and stimulates the enzymatic activity of MAP kinases upon wide variety of extra- and intracellular signals. As a key player of MAP kinase signal transduction pathway, MEK1 is involved in many cellular processes such as proliferation, differentiation, transcription regulation and development. MAP2K1 catalyzes the concomitant phosphorylation of a threonine and a tyrosine residue in a thr-glu-tyr sequence located in map kinases. MEK1 activates erk1 and erk2 map kinases.

MAP kinase-activated protein kinase 3 (MAPKAPK3) is involved in inflammatory Reaction by regulating tumor necrosis factor (TNF) and IL6 production post-transcriptionally. MAPKAPK3 phosphorylates AU-rich elements (AREs)-binding proteins, like TTP/ZFP36, leading to control of stability and translation of TNF and IL6 mRNAs. Phosphorylation of TTP/ZFP36 (a major post-transcriptional regulator of TNF), promotes its binding to 14-3-3 proteins and reduces its ARE mRNA affinity resulting in inhibition of dependent degradation of ARE-containing transcript. MAPKAPK3 is activated by growth inducers and stress stimulation of cells.

MAPK13 belongs to the MAP kinase family. MAP kinases perform as an incorporation point for various biochemical signals. MAP kinases take part in an extensive range of cellular courses like differentiation, development, transcription regulation and proliferation. MAPK13 is phosphorylated by MKK6 as a reaction to cytokines and cellular stresses.

COAA is a member of the prokaryotic pantothenate kinase family and it is the first enzyme in the Coenzyme A biosynthetic pathway. COAA phosphorylates pantothenate (vitamin B5) to form 4'-phosphopantothenate. The key factor controlling the intracellular CoA concentration is the regulation of COAA activity by feedback inhibition.

pykF (pyruvate kinase I) is a member of the pyruvate kinase family. pykF is an enzyme involved in glycolysis. pykF catalyzes the transfer of a phosphate group from phosphoenolpyruvate (PEP) to ADP, yielding one molecule of pyruvate and one molecule of ATP, a process which also requires a Magnesium ion. This is the final step in the glycolytic pathway, which produces pyruvate molecules, the ultimate product of aerobic glycolysis.

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.

CKS2 protein binds to the catalytic subunit of the cyclin dependent kinases and is necessary for their biological function. The CKS2 mRNA is expressed in various patterns through the cell cycle in HeLa cells, which shows spcific role for the encoded protein. CKS2 (CDC28) Protein kinase 2 binds to the catalytic subunit of cyclin-dependent kinases and has thus in involved in cell cycle regulation. CKS2 is required for the first metaphase/anaphase transition during the meiosis. An increase in expression of CKS2 protects the cells from apoptosis. CKS2 is essential during early embryogenesis and cell cycle progression in somatic cells.

Creatine Kinase BB is a cytoplasmic enzyme involved in energy homeostasis. The encoded protein reversibly catalyzes the transfer of phosphate between ATP and various phosphogens such as creatine phosphate. It acts as a homodimer in brain as well as in other tissues, and as a heterodimer with a similar muscle isozyme in heart. The encoded protein is a member of the ATP:guanido phosphotransferase protein family. A pseudogene of this gene has been characterized.

UCK2 is a member of the uridinekinase family. UCK2 catalyzes the phosphorylation of uridine monophosphate to uridine diphosphate and cytidine monophosphate. UCK2 has a part in the production of pyrimidine nucleoside triphosphates essential for RNA and DNA synthesis. Furthermore, an allele of this gene is an important player in mediating nonhumoral immunity to Hemophilus influenzae type B.

UCK1 is a uridine-cytidine kinase which catalyzes the phosphorylation of uridine and cytidine to uridine monophosphate and cytidine monophosphate. UCK1 does not phosphorylate deoxyribonucleosides or purine ribonucleosides. UCK1 is also phosphorylates uridine and cytidine analogs and uses ATP and GTP as a phosphate donor.

Testis-specific serine/threonine-protein kinase 6 (TSSK6) is an intronless gene, which belongs to the CAMK Ser/Thr protein kinase family. The TSSK6 protein contains one protein kinase domain. TSSK6 is highly expressed in the testis and lowly expressed in the colon, prostate, thymus, small intestine, and peripheral blood leukocytes. TSSK6 interacts with the heatshock proteins HSPA8, HSPCB, and HAPA1A; these interactions seem to be essential for TSSK6 kinase activity. TSSK6 plays a role in DNA condensation during postmeiotic chromatin remodeling. In addition, TSSK6 is required for sperm production and function.

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.

GlpK also known as glycerol kinase, is a member of the FGGY kinase family. GlpK catalyzes the transfer of a phosphate group from ATP to glycerol, thereby forming glycerol phosphate. Furthermore, this intermediate can then be converted to dihydroxyacetone phosphate (DHAP), which is utilized in either glycolysis or gluconeogenesis. The activity of GlpK is affected by numerous metabolites. The non-competitive allosteric inhibition by fructose 1,6-bisphosphate (FBP) triggers modifications in the quaternary structure of Glpk.

Protein Kinase IFN Double Stranded RNA Activator, also known as PRKRA, mediates the effects of interferon when a viral infection takes place. PRKRA activates EIF2AK2/PKR in the absence of double-stranded RNA (dsRNA) and leads to phosphorylation of EIF2S1/EFI2-alpha and inhibition of translation and induction of apoptosis. Mutations in PRKRA are associated with dystonia.

cAMP-dependent protein kinase type II-alpha regulatory subunit (PRKAR2A) can be phosphorylated by the activated catalytic subunit. PRKAR2A interacts with numerous A-kinase anchoring proteins and regulates the subcellular localization of cAMP-dependent protein kinase.

Glucokinase or GLK, is a protein, part of the bacterial glucokinase superfamily. In the bacteria E. coli, glucose can be transported to the inner cell through a system called PTS as glucose 6-phosphate, therefore, GLK is less crucial to the bacteria.

Glucokinase also known as GLK is a member of the bacterial glucokinase family. GLK is not highly significant in E.coli since glucoseis already transported into the cell through the PTS system as glucose 6-phosphate.

PRKAG1 is a regulatory subunit of the AMP-activated protein kinase (AMPK). AMPK is a heterotrimer comprised of an alpha catalytic subunit, and non-catalytic beta and gamma subunits. AMPK is a vital energy-sensing enzyme which supervises cellular energy status. PRKAG1 is one of the gamma regulatory subunits of AMPK. Alternatively spliced transcript variants encoding dissimilar isoforms were found.

Protein Kinase CAMP-Dependent Catalytic Beta (PRKACB) belongs to the Ser/Thr protein kinase family and is a catalytic subunit of cAMP-dependent protein kinase. cAMP is a signaling molecule imperative for various cellular functions. cAMP activates the cAMP-dependent protein kinase, which transduces the signal by way of phosphorylation of different target proteins. The inactive kinase holoenzyme is a tetramer composed of 2 regulatory and 2 catalytic subunits. cAMP triggers the dissociation of the inactive holoenzyme into a dimer of regulatory subunits bound to 4 cAMP and 2 free monomeric catalytic subunits. PRKACB mediates cAMP-dependent signaling initiated by receptor binding to GPCRs. PKA activation regulates various cellular processes such as cell proliferation, the cell cycle, differentiation and regulation of microtubule dynamics, chromatin condensation and decondensation, nuclear envelope disassembly and reassembly, in addition to regulation of intracellular transport mechanisms and ion flux. PRKACB regulates the abundance of compartmentalized pools of its regulatory subunits via phosphorylation of PJA2 which binds and ubiquitinates these subunits, leading to their consequent proteolysis.

PRKAB2 is a regulatory subunit of the AMP-activated protein kinase (AMPK). AMPK is a heterotrimer contains an alpha catalytic subunit and non-catalytic beta and gamma subunits. AMPK is a significant energy-sensing enzyme that supervises cellular energy status. AMPK is activated as a reply to cellular metabolic stresses, therefore phosphorylates and inactivates acetyl-CoA carboxylase (ACC) and beta-hydroxy beta-methylglutaryl-CoA reductase (HMGCR), vital enzymes involved in regulating de novo biosynthesis of fatty acid and cholesterol. PRKAB2 is a positive regulator of AMPK activity and highly expressed in skeletal muscle.

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).

Protein Kinase, AMP-Activated, Alpha 1 (PRKAA1) is a protein coding gene which is the catalytic subunit of AMPK. AMPK is an energy sensor protein kinase which regulates cellular energy metabolism. AMPK adjusts the activity of various important metabolic enzymes by direct phosphorylation. Among its other features, AMPK protects cells from stresses that cause ATP depletion by switching off ATP-consuming biosynthetic pathways.

Tribbles Pseudokinase 3, also known as TRIB3, is a putative protein kinase which is induced by the transcription factor NF-kappaB. In addition, TRIB3 is a negative regulator of NF-kappaB, and can as well sensitize cells to TNF- and TRAIL-induced apoptosis. Furthermore, TRIB3 is able to negatively regulate the cell survival serine-threonine kinase AKT1. One of the diseases which are associated with TRIB3 is anoxia.

TPMT, thiopurine S-methyltransferase, is a cytosolic enzyme that metabolizes thiopurine drugs via S-adenosyl-L-methionine as the S-methyl donor and S-adenosyl-L-homocysteine as a byproduct. TPMT activity exhibits autosomal codominant genetic polymorphism, and patients inheriting TPMT-deficiency are at high risk of potentially fatal hematopoietic toxicity.

Thiamin pyrophosphokinase 1 (TPK1) is a homodimer which catalyzes the phosphorylation of thiamine to thiamine pyrophosphate. TPK1 is found in the heart, kidney, testis, small intestine and peripheral blood leukocytes, and at very low levels in a variety of tissues. TPK1 gene defects cause the thiamine metabolism dysfunction syndrome type 5, episodic encephalopathy type (THMD5), which is an autosomal recessive metabolic disorder due to an inborn error of thiamine metabolism.

GALK1 enzyme is needed in the first step of the galactose metabolism pathway.
(ATP + D-galactose = ADP + alpha-D-galactose 1-phosphate). GALK1 deficinecy lead galactosemia II which is an autosomal recessive deficiency known by congenital cataracts during infancy and presenile cataracts in the adult population. The cataracts are secondary to accumulation of galactitol in the lenses.

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.

KIT, also known as KIT Proto-Oncogene Receptor Tyrosine, is a cytokine receptor which is expressed not only in hematopoietic stem cells but likewise in other cell types. KIT binds to receptor tyrosine kinase type III, which is a stem cell factor, also named a "rigid factor" or "c-kit ligand". Once this receptor binds to stem cell factor (SCF), it forms a dimer which activates intrinsic tyrosine kinase activity, which sequentially phosphorylates & activates signaling molecules which breed signals in cells. This receptor protects vascular smooth muscle cells from apoptosis in addition to restoring cardiac function after myocardial infarction.

Ketohexokinase catalyzes the phosphorylation of fructose to produce fructose-1-phosphate, resulting in the utilization of ATP and creation of AMP. Ketohexokinase commences initial step in the metabolism of dietary fructose and is a significant regulator of hepatic glucose metabolism. Ketohexokinase is found in liver, renal cortex, and small intestine. Its deficiency causes the benign hereditary metabolic disorder essential fructosuria, leading to fructose being excreted in the urine. Ketohexokinase-dependent metabolism of fructose induces proinflammatory mediators in proximal tubular cells. ketohexokinase plays an unknown physiologic function that remains intact in essential fructosuria. Ketohexokinase expression is reduceed in human clear cell type of renal cell carcinoma.

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.

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.

PKLR is a pyruvate kinase which catalyzes the transphosphorylation of phohsphoenolpyruvate into pyruvate and ATP. That is the rate-limiting step of glycolysis. PKLR gene encodes the L- and R-type isoenzymes through alternate splicing events controlled by different promoters. L-type isoform can also appear as a tetramer and is upregulated by glucose with implications in maturity-onset diabetes of the young.

cAMP-dependent protein kinase inhibitor beta (PKIB) belongs to the cAMP-dependent protein kinase inhibitor family. PKIB may interact with the catalytic subunit of cAMP-dependent protein kinase and function as a competitive inhibitor.

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 2 mitochondrial (TK2) is a member of the DCK/DGK family. TK2 is an enzyme, a phosphotransferase (a kinase): 2'-deoxythymidine kinase, ATP-thymidine 5'-phosphotransferase. Thymidine kinase is found in most living cells. Thymidine kinase is present in 2 forms in mammalian cells, TK1 and TK2. Thymidine kinases have a central function in the synthesis of DNA and thus in cell division, since they are part of the exceptional reaction chain to introduce deoxythymidine into the DNA. TK2 is a deoxyribonucleoside kinase which specifically phosphorylates thymidine, deoxycytidine, and deoxyuridine. TK2 localizes to the mitochondria and is essential for mitochondrial DNA synthesis. TK2 gene defects are a cause of mitochondrial DNA depletion syndrome type 2 (MTDPS2).

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.

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.

Phosphatidylinositol-5-Phosphate 4-Kinase, Type II, Beta (PIP4K2B) belongs to the phosphatidylinositol-4-phosphate 5-kinase family.PIP4K2B catalyzes the phosphorylation of phosphatidylinositol-4-phosphate on the 5th hydroxyl of the myo-inositol ring to form phosphatidylinositol-4,5-bisphosphate. PIP4K2B amino acid sequence does not show resemblance to another kinases although PIP4K2B presents kinase activity.PIP4K2B also interacts with p55 TNF receptor.

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.

TIE1 is an angiopoitein receptor which takes part in hematopoiesis,angiogenesis and vasculogenesis.TIE1 is expressed primarily on endothelial and hematopoietic progenitor cells. TIE1 is expressed in immature hematopoietic Recombinant Human TIE1 protein cells and platelets. TIE1 upregulates the cell adhesion molecules(CAMs) VCAM-1,ICAM-1 and E-selectinthrough a p38-dependent mechanism. TIE1 has a proinflammatory effect and takes part in the endothelial inflammatory diseases such as atherosclerosis.

Protein Interacting with PRKCA 1, also known as PICK1 includes a PDZ domain, through which it interacts with protein kinase C, alpha (PRKCA). PICK1 performs as an adaptor which binds to and arranges the subcellular localization of various membrane proteins. PICK1 interacts with multiple glutamate receptor subtypes, monoamine plasma membrane transporters, in addition to non-voltage gated sodium channels, and might target PRKCA to these membrane proteins and therefore regulates their distribution as well as function. PICK1 has also been found to perform as an anchoring protein which particularly targets PRKCA to mitochondria in a ligand-specific manner.

Inositol Hexakisphosphate Kinase 2 (IP6K2) which is a part of the inositol IPK family converts inositol hexakisphosphate to diphosphoinositol pentakisphosphate. IP6K2 also converts 1, 3, 4, 5, 6-pentakisphosphate (InsP5) to PP-InsP4. IP6K2 is a protein coding gene which suppresses the growth and affects the apoptotic activities of IFN-beta in several ovarian cancers.

Flavokinase is a transferases family member, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor. Flavokinase is an enzyme that catalyzes the phosphorylation of riboflavin (vitamin B2) to form flavin-mononucleotide (FMN), which is an obligatory step in vitamin B2 utilization and flavin cofactor synthesis. It has been proposed that TNF, through the activation of the RFK gene, enhances the incorporation of FAD in NADPH oxidase enzymes, which is a critical step for the assembly and activation of NADPH oxidase.

PGK2, also known as Phosphoglycerate kinase 2, is a testis-specific form of phosphoglycerate kinase.Originally, it was assumed that PGK2was a pseudogene. However, nowadays it is known that this protein is a functional phosphoglycerate kinase. During the Embden-Meyerhof-Parnas pathway of glycolysis, in thelater stages of spermatogenesis, the protein catalyses the reversible conversion of 1, 3- bisphosphoglycerate to 3-phosphoglycerate.

PGK2 is a testis-specific form of phosphoglycerate kinase. Originally presumed to be a pseudogene, the PGK2 protein is actually a functional phosphoglycerate kinase which catalyzes the reversible conversion of 1,3-bisphosphoglycerate to 3-phosphoglycerate, during the Embden-Meyerhof-Parnas pathway of glycolysis, in the later stages of spermatogenesis. The PGK2 gene is intronless, results from retrotransposition of the phosphoglycerate kinase 1 gene, and is expressed specifically in the testis.

PGK1 is an X-linked enzyme that has a major role in the glycolytic pathway. PGK1 is a glycolytic enzyme which catalyzes the conversion of 1,3-diphosphoglycerate to 3-phosphoglycerate, generating an ATP molecule. PGK1 may also act as a cofactor for polymerase alpha. Defects in the PGK1 gene are usually associated with chronic hemolytic anemia, though it can be accompanied by either mental retardation or muscular disease (rhabdomyolysis). Overexpression of PGK1 and its signalling targets are possibly an expression-pathway in diffuse primary gastric carcinomas promoting peritoneal dissemination. It was shown that PGK1 is differentially expressed in the dorsolateral prefrontal cortex from patients with schizophrenia.

Phosphoglycerate kinase 1, also referred to PGK1, is an X-linked enzyme whichfunctions in the glycolytic pathway.The gene encoding the erythrocyte enzyme PGK1 & it seems that PGK-1 plays a role as a polymerase alpha cofactor protein (primer recognition protein) as a glyxolytic enzyme role. The PGK1 catalyzes the reversible conversion of 1, 3-diphosphoglycerate to 3-phosphoglycerate during glycolysis, generating one molecule of ATP.

PGK1 is an X-linked enzyme that has a major role in the glycolytic pathway. PGK1 is a glycolytic enzyme which catalyzes the conversion of 1,3-diphosphoglycerate to 3-phosphoglycerate, generating an ATP molecule. PGK1 may also act as a cofactor for polymerase alpha. Defects in the PGK1 gene are usually associated with chronic hemolytic anemia, though it can be accompanied by either mental retardation or muscular disease (rhabdomyolysis). Overexpression of PGK1 and its signalling targets are possibly an expression-pathway in diffuse primary gastric carcinomas promoting peritoneal dissemination. It was shown that PGK1 is differentially expressed in the dorsolateral prefrontal cortex from patients with schizophrenia.

ILK1 (Integrin-linked kinase) is a serine/threonine protein kinase, containing 4 ankyrin-like repeats. ILK1 regulates a number of biological properties which include: anchorage-independent cell cycle progression, tumor cell invasion and apoptosis. ILK1 can also be implicated in mediating cell architecture, adhesion to integrin substrates and anchorage-dependent growth in epithelial cells. Furthermore, ILK1 phosphorylates beta-1 and beta-3 integrin subunit on serine and threonine residues, but also AKT1 and GSK3B.
ILK1 interacts with the cytoplasmic domains of integrin ?1 and ?3 subunits in addition to several adaptors and signaling proteins, it also acts as a proximal receptor kinase regulating integrin-mediated signal transduction. ILK1 is a focal adhesion protein part of the complex ILK-PINCH. This complex is deemed to be one of the convergence points of integrin- and growth factor-signaling pathway. ILK1 is stimulated rapidly but briefly by both cell fibronectin interactions in a PI3-K-dependent manner, probably through the binding of PtdIns(3,4,5)P3 with a PH-like domain of ILK.
ILK1 over-expression has been documented in a wide variety of human malignancies.