Map Key
Generic Enzyme
Generic kinase
Protein kinase
Lipid kinase
Generic phosphatase
Protein phosphatase
Lipid phosphatase
Generic phospholipase
Generic protease
Metalloprotease
G-alpha
RAS - superfamily
G beta/gamma
Regulators (GDI, GAP, GEF)
Generic channel
Ligand-gated channel
Voltage-gated channel
Transporter
Normal process
Pathological process
Positive effect
Negative effect
Unspecified effect
Technical link
Disrupts in disease
Emerges in disease
Enhances in disease
Weakens in disease
Organsim specific interaction

Generic binding protein
Receptor ligand
Cell membrane glycoprotein
Transcription factor
DNA
RNA
Compound
Inorganic ion
Predicted metabolite or user's structure
Reaction
Generic receptor
GPCR
Receptors with enzyme activity
Mitochondria
EPR
Golgi
Nucleus
Lysosome
Peroxisome
Cytoplasm
Extracellular

Normal process
Pathological process
Binding
Cleavage
Covalent modifications
Phosphorylation
Dephosphorylation
Transformation
Transport
Catalysis
Transcription regulation
MicroRNA binding
Competition
Influence on expression
Unspecified interactions
Pharmacological effect
Toxic effect
Group relation
Complex subunit
Similarity reaction
A complex or a group
Organism specific object

ATP/ITP metabolism


Log In to Post A Comment

ATP/ITP metabolism

ATP/ITP metabolism

ATP plays the important role in a metabolism. This compound is a universalenergy source for all biochemical processes occurring in live systems. Knowledge ofInosine metabolism has led to advances in immunotherapy inrecent decades.

ATP is often used as a phosphate source, e.g., in the reaction with Neopterindiphosphate ( NDP ) that results in formation of ADP andNeopterin-3'-triphosphate ( NTP ), as well as in the reaction with Inosinediphosphate ( IDP ) in which Inosine triphosphate ( ITP ) is formed. Thesereactions are catalyzed by similar enzymes, Nucleoside diphosphate kinase ( NDPKcomplex) [1], [2], [3], [4], [5], Non-metastatic cells 4, protein expressed in ( NDPK D (mitochondrial) )[6], [7], [8], Non-metastatic cells 3, proteinexpressed in ( NDPK C ) [9], [10], [7],Nucleoside non-metastatic cells 6, protein expressed in (nucleoside-diphosphate kinase) (NDPK 6 ) [11], [8], Non-metastatic cells 7, proteinexpressed in (nucleoside-diphosphate kinase) ( NDPK 7 ) [8] andnon-metastatic cells 2, protein (NM23B) expressed in, pseudogene 1 ( NDPK 8 )[12].

Hydrolysis of ATP to ADP proceeds in two ways and catalyzed by specificgroups of enzymes. The first group consists of Ectonucleoside triphosphatediphosphohydrolase 2 ( ENTPD2-alpha ) [13], [14],Ectonucleoside triphosphate diphosphohydrolase 1 ( ENP1 ) [15], [16], [17], [18], Ectonucleoside triphosphatediphosphohydrolase 3 ( ENP3 ) [19], [20], [21],Acylphosphatase 1, erythrocyte (common) type ( ACYP1 ) [22], [23], Acylphosphatase 2, muscle type ( ACYP2 ) [22], [23], Acid phosphatase 5, tartrate resistant ( PPA5 ) [24],[25], Epoxide hydrolase 2, cytoplasmic ( EPHX2 ) [26], andAlkaline phosphatase, placental (Regan isozyme) ( ALPP ) [26]. Thesecond group consists of Acid phosphatase 2, lysosomal ( PPAL ) [27],[28], [29], Acid phosphatase 5, tartrate resistant ( PPA5 )[30], [31], [32], [33], and Acid phosphatase,prostate ( PPAP ) [34], [35], [36], [37]. Second group also catalyzes further hydrolysis of ADP to AMP andAMP to release Adenosine.

There are two processes that lead to ITP hydrolysis. The first is a reactioncatalyzed by Ectonucleoside triphosphate diphosphohydrolase 1 ( ENP1 ) [15], [19], [18], Ectonucleoside triphosphatediphosphohydrolase 3 ( ENP3 ) [19], [20], [21],and Ectonucleoside triphosphate diphosphohydrolase 6 (putative function) ( ENTPD6) [38], [39]. It results in formation of IDP. Theseenzymes also participate in the following hydrolysis of IDP to Inosinemonophosphate ( IMP). And in the second case ITP is hydrolyzed directly toIMP by the action Inosine triphosphatase (nucleoside triphosphate pyrophosphatase)( ITPA ) [40], [41], [42], [43].

Yet another process leading to formation of ADP is the reaction of ATPwith AMP catalyzed by Adenylate kinase 5 ( AK5 ) [44],Adenylate kinase 1 ( AK1 ) [45], [44], Adenylate kinase 2 (AK2 ) [45], [44], Adenylate kinase 3-like 1 ( AK3 )[46], [44], TAF9 RNA polymerase II, TATA box binding protein(TBP)-associated factor, 32kDa ( KAD6 ) [47], [48], andAdenylate kinase 7 ( KAD7 ) [49], [50].

ADP can participate in reaction of formation of 2 '-deoxy-ADP ( dADP ). Thisreaction is catalyzed by Ribonucleotide reductase. This enzyme is involved in onemore reaction of formation of 2 '-deoxy-IDP ( dIDP ) from IDP [51], [52], [53], [54], [55]. dADPand dIDP take part in the dATP/dITP metabolism.

AMP can be hydrolyzed to IMP via two pathways. The first is a directhydrolysis catalyzed by AMP deaminase [56], [57], Adenosinemonophosphate deaminase 2 (isoform L) AMP deaminase 2 [58], [59], [60], Adenosine monophosphate deaminase 1 (isoform M) AMPdeaminase 1 [61], [62], [63], [64], andAdenosine monophosphate deaminase (isoform E) ( AMD3 ) [65], [66], [67], [68]. The second is represented by a chain ofconsecutive reactions: formation of Adenylo-succinate catalyzed byAdenylosuccinate lyase ( ADSL ) [69], [70], [71],[72], [73] followed by formation of IMP in the presenceof Adenylosuccinate synthase ( ADSS ) [74], [75], [76], [77] and Adenylosuccinate synthase like 1 ( ADSSL1 ) [74], [75], [76], [77], [78].IMP also takes part in IMP biosynthesis and GTP-XTP metabolism.

AMP can directly form Adenine, this reaction occurs in the presence ofAdenine phosphoribosyltransferase ( APRT ) [79], [80],[81]. Similar reaction proceeds for IMP from Hypoxanthine underthe action of Hypoxanthine phosphoribosyltransferase 1 ( HPRT ) [82],[83], [84], [85], [86]. Adenine andHypoxanthine participate in other processes, e.g., dATP/dITP metabolism and inGTP-XTP metabolism.

Nucleoside phosphorylase ( PNPH ) catalyzes the formation of Adeninefrom Adenosine [87], [88], [89] andInosine from Hypoxanthine [90], [91], [92], [87], [88], [89]. Inosine can also beproduced as a result of hydrolysis of Adenosine by Adenosine deaminase (ADA ) [93], [94], [95], Adenosine deaminase,RNA-specific ( ADAR1 ) [96], Adenosine deaminase, RNA-specific, B1(RED1 homolog rat) ( ADAR2 ) [96] Adenosine deaminase, RNA-specific,B2 (RED2 homolog rat) ( ADAR3 ) [96].