Purine nucleoside phosphorylase

Not to be confused with polynucleotide phosphorylase.

purine-nucleoside phosphorylase
Identifiers
EC number	2.4.2.1
CAS number	9030-21-1
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / EGO
Search PMC articles PubMed articles

Purine nucleoside phosphorylase
PDB rendering based on 1m73.
Available structures PDB 1M73, 1PF7, 1PWY, 1RCT, 1RFG, 1RR6, 1RSZ, 1RT9, 1ULA, 1ULB, 1V2H, 1V3Q, 1V41, 1V45, 1YRY, 2A0W, 2A0X, 2A0Y, 2OC4, 2OC9, 2ON6, 2Q7O, 3BGS, 3D1V, 3GB9, 3GGS, 3K8O, 3K8Q
Identifiers
Symbols	PNP; FLJ94043; FLJ97288; FLJ97312; MGC117396; MGC125915; MGC125916; NP; PRO1837; PUNP
External IDs	OMIM: 164050 MGI: 97365 HomoloGene: 227 GeneCards: PNP Gene
EC number	2.4.2.1
Gene Ontology Molecular function • nucleoside binding • purine base binding • purine-nucleoside phosphorylase activity • purine-nucleoside phosphorylase activity • drug binding • phosphate binding Cellular component • intracellular • cytoplasm • cytosol • cytoskeleton Biological process • nucleobase, nucleoside, nucleotide and nucleic acid metabolic process • purine base metabolic process • inosine catabolic process • purine nucleotide catabolic process • nicotinamide riboside catabolic process • immune response • nucleoside metabolic process • NAD biosynthesis via nicotinamide riboside salvage pathway • urate biosynthetic process • positive regulation of T cell proliferation • response to drug • response to drug • purine-containing compound salvage • positive regulation of alpha-beta T cell differentiation • nucleobase, nucleoside and nucleotide metabolic process • interleukin-2 secretion Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	4860	18950
Ensembl	ENSG00000198805	ENSMUSG00000021871
UniProt	P00491	P23492
RefSeq (mRNA)	NM_000270.3	NM_013632.4
RefSeq (protein)	NP_000261.2	NP_038660.1
Location (UCSC)	Chr 14: 20.94 – 20.95 Mb	Chr 14: 51.56 – 51.57 Mb
PubMed search	[1]	[2]

Purine nucleoside phosphorylase also known as PNPase and inosine phosphorylase is an enzyme that in humans is encoded by the NP gene.^[1]

Function

Purine nucleoside phosphorylase is an enzyme involved in purine metabolism. PNP metabolizes adenosine into adenine, inosine into hypoxanthine, and guanosine into guanine, in each case creating ribose phosphate.

Nucleoside phosphorylase is an enzyme which cleaves a nucleoside by phosphorylating the ribose to produce a nucleobase and ribose 1 phosphate. It is one enzyme of the nucleotide salvage pathways. These pathways allow the cell to produce nucleotide monophosphates when the de novo synthesis pathway has been interrupted or is non-existent (as is the case in the brain). Often the de novo pathway is interrupted as a result of chemotherapy drugs such as methotrexate or aminopterin.

All salvage pathway enzymes require a high energy phosphate donor such as ATP or PRPP.

• Thymidine can be phosphorylated by thymidine kinase (TK).
• Uridine can be phosphorylated by uridine kinase (UK).
• Cytidine can be phosphorylated by cytidine kinase (CK).
• Deoxycytidine can be phosphorylated by deoxycytidine kinase (DOK).

Adenosine uses the enzyme adenosine kinase, which is a very important enzyme in the cell. Attempts are being made to develop an inhibitor for the enzyme for use in cancer chemotherapy.

Clinical significance

PNPase together with adenosine deaminase (ADA), serves a key role in purine catabolism, referred to as the salvage pathway. Mutations in ADA lead to an accumulation of (d)ATP, which inhibits ribonucleotide reductase, leading to a deficiency in (d)CTPs and (d)TTPs, which, in turn, induces apoptosis in T-lymphocytes and B-lymphocytes, leading to severe combined immunodeficiency (SCID).^{[citation needed]}

PNP-deficient patients will have an immunodeficiency problem. It affects only T-cells; B-cells are unaffected by the deficiency.

See also

• Purine nucleoside phosphorylase deficiency

References

1. ^ "Entrez Gene: NP nucleoside phosphorylase". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=4860. 

Further reading

• Markert ML (1991). "Purine nucleoside phosphorylase deficiency.". Immunodeficiency reviews 3 (1): 45–81. PMID 1931007. 
• Borgers M, Verhaegen H, De Brabander M, et al. (1978). "Purine nucleoside phosphorylase in chronic lymphocytic leukemia (CLL).". Blood 52 (5): 886–95. PMID 100152. 
• Aust MR, Andrews LG, Barrett MJ, et al. (1992). "Molecular analysis of mutations in a patient with purine nucleoside phosphorylase deficiency.". Am. J. Hum. Genet. 51 (4): 763–72. PMC 1682776. PMID 1384322. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1682776. 
• Andrews LG, Markert ML (1992). "Exon skipping in purine nucleoside phosphorylase mRNA processing leading to severe immunodeficiency.". J. Biol. Chem. 267 (11): 7834–8. PMID 1560016. 
• Jonsson JJ, Williams SR, McIvor RS (1991). "Sequence and functional characterization of the human purine nucleoside phosphorylase promoter.". Nucleic Acids Res. 19 (18): 5015–20. doi:10.1093/nar/19.18.5015. PMC 328804. PMID 1923769. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=328804. 
• Ealick SE, Rule SA, Carter DC, et al. (1990). "Three-dimensional structure of human erythrocytic purine nucleoside phosphorylase at 3.2 A resolution.". J. Biol. Chem. 265 (3): 1812–20. PMID 2104852. 
• Williams SR, Gekeler V, McIvor RS, Martin DW (1987). "A human purine nucleoside phosphorylase deficiency caused by a single base change.". J. Biol. Chem. 262 (5): 2332–8. PMID 3029074. 
• Williams SR, Goddard JM, Martin DW (1984). "Human purine nucleoside phosphorylase cDNA sequence and genomic clone characterization.". Nucleic Acids Res. 12 (14): 5779–87. doi:10.1093/nar/12.14.5779. PMC 320030. PMID 6087295. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=320030. 
• Pannicke U, Tuchschmid P, Friedrich W, et al. (1997). "Two novel missense and frameshift mutations in exons 5 and 6 of the purine nucleoside phosphorylase (PNP) gene in a severe combined immunodeficiency (SCID) patient.". Hum. Genet. 98 (6): 706–9. doi:10.1007/s004390050290. PMID 8931706. 
• Markert ML, Finkel BD, McLaughlin TM, et al. (1997). "Mutations in purine nucleoside phosphorylase deficiency.". Hum. Mutat. 9 (2): 118–21. doi:10.1002/(SICI)1098-1004(1997)9:2<118::AID-HUMU3>3.0.CO;2-5. PMID 9067751. 
• Erion MD, Takabayashi K, Smith HB, et al. (1997). "Purine nucleoside phosphorylase. 1. Structure-function studies.". Biochemistry 36 (39): 11725–34. doi:10.1021/bi961969w. PMID 9305962. 
• Erion MD, Stoeckler JD, Guida WC, et al. (1997). "Purine nucleoside phosphorylase. 2. Catalytic mechanism.". Biochemistry 36 (39): 11735–48. doi:10.1021/bi961970v. PMID 9305963. 
• Stoeckler JD, Poirot AF, Smith RM, et al. (1997). "Purine nucleoside phosphorylase. 3. Reversal of purine base specificity by site-directed mutagenesis.". Biochemistry 36 (39): 11749–56. doi:10.1021/bi961971n. PMID 9305964. 
• Sasaki Y, Iseki M, Yamaguchi S, et al. (1998). "Direct evidence of autosomal recessive inheritance of Arg24 to termination codon in purine nucleoside phosphorylase gene in a family with a severe combined immunodeficiency patient.". Hum. Genet. 103 (1): 81–5. doi:10.1007/s004390050787. PMID 9737781. 
• Sheppard TL, Ordoukhanian P, Joyce GF (2000). "A DNA enzyme with N-glycosylase activity.". Proc. Natl. Acad. Sci. U.S.A. 97 (14): 7802–7. doi:10.1073/pnas.97.14.7802. PMC 16625. PMID 10884411. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=16625. 
• Dalal I, Grunebaum E, Cohen A, Roifman CM (2001). "Two novel mutations in a purine nucleoside phosphorylase (PNP)-deficient patient.". Clin. Genet. 59 (6): 430–7. doi:10.1034/j.1399-0004.2001.590608.x. PMID 11453975. 
• Ivings L, Pennington SR, Jenkins R, et al. (2002). "Identification of Ca2+-dependent binding partners for the neuronal calcium sensor protein neurocalcin delta: interaction with actin, clathrin and tubulin.". Biochem. J. 363 (Pt 3): 599–608. doi:10.1042/0264-6021:3630599. PMC 1222513. PMID 11964161. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1222513. 
• Falkenberg M, Gaspari M, Rantanen A, et al. (2002). "Mitochondrial transcription factors B1 and B2 activate transcription of human mtDNA.". Nat. Genet. 31 (3): 289–94. doi:10.1038/ng909. PMID 12068295. 
• Stoychev G, Kierdaszuk B, Shugar D (2002). "Xanthosine and xanthine. Substrate properties with purine nucleoside phosphorylases, and relevance to other enzyme systems.". Eur. J. Biochem. 269 (16): 4048–57. doi:10.1046/j.1432-1033.2002.03097.x. PMID 12180982. 

External links

• Human PNP at Cornell University
• E. Coli PNP at Cornell University
• MeSH Purine-Nucleoside+Phosphorylase

This transferase article is a stub. You can help Wikipedia by expanding it.v · Categories: Human proteins Transferase stubs Wikimedia Foundation. 2010. Игры ⚽ Нужен реферат? Versus the World (band) Nordica Look at other dictionaries: purine nucleoside phosphorylase — purine nucleoside phosphorylase, an enzyme that keeps T cells functioning by cleansing them of contaminants: »Purine nucleoside phosphorylase…cleans up metabolic debris that would otherwise build up inside the T cells and shut them down (Jane E.… …   Useful english dictionary purine nucleoside phosphorylase — purine nucleoside phosphorylase. См. пурин нуклеозидфосфорилаза. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь. Purine-nucleoside phosphorylase — In enzymology, a purine nucleoside phosphorylase (EC number|2.4.2.1) is an enzyme that catalyzes the chemical reaction:purine nucleoside + phosphate ightleftharpoons purine + alpha D ribose 1 phosphateThus, the two substrates of this enzyme are… …   Wikipedia Purine nucleoside phosphorylase deficiency — Infobox Disease Name = PAGENAME Caption = DiseasesDB = 11044 ICD10 = ICD10|D|81|5|d|80 ICD9 = ICD9|277.2 ICDO = OMIM = 164050 MedlinePlus = eMedicineSubj = ped eMedicineTopic = 1957 MeshID = Purine nucleoside phosphorylase deficiency, often… …   Wikipedia purine-nucleoside phosphorylase — pu·rine nu·cleo·side phos·phor·y·lase (puґrēn nooґkle o sīd fos forґə lās) [EC 2.4.2.1] an enzyme of the transferase class that catalyzes the cleavage of purine nucleosides to form purines and ribose 1 phosphates in the… …   Medical dictionary Deficit en purine nucleoside phosphorylase — Déficit en purine nucléoside phosphorylase Le déficit en purine nucléoside phosphorylase entre dans le cadre d un déficit immunitaire congénital. Il existe un déficit de l immunité cellulaire et une anomalie de production de certains anticorps.… …   Wikipédia en Français Déficit En Purine Nucléoside Phosphorylase — Le déficit en purine nucléoside phosphorylase entre dans le cadre d un déficit immunitaire congénital. Il existe un déficit de l immunité cellulaire et une anomalie de production de certains anticorps. Sa transmission est autosomique dominante.… …   Wikipédia en Français Déficit en purine nucléoside phosphorylase — Le déficit en purine nucléoside phosphorylase entre dans le cadre d un déficit immunitaire congénital. Il existe un déficit de l immunité cellulaire et une anomalie de production de certains anticorps. Sa transmission est autosomique dominante.… …   Wikipédia en Français Nucleoside phosphorylase — Nucleoside phosphorylase, also known as NP, is a human gene.cite web | title = Entrez Gene: NP nucleoside phosphorylase| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene Cmd=ShowDetailView TermToSearch=4860| accessdate = ] PBB Summary… …   Wikipedia nucleoside phosphorylase — n NUCLEOSIDASE (2) * * * nu·cleo·side phos·phor·y·lase (nooґkle o sīd″ fos forґə lās) any of the enzymes of the sub subclass pentosyltransferases [EC 2.4.2] that catalyze the phosphorolysis of a nucleoside to form the free… …   Medical dictionary 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”