where the two substrates of this enzyme are CTP and choline phosphate, and the two products are diphosphate and CDP-choline. It is responsible for regulating phosphatidylcholine content in membranes.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is CTP:choline-phosphate cytidylyltransferase. Other names in common use include phosphorylcholine transferase, CDP-choline pyrophosphorylase, CDP-choline synthetase, choline phosphate cytidylyltransferase, CTP-phosphocholine cytidylyltransferase, CTP:phosphorylcholine cytidylyltransferase, cytidine diphosphocholine pyrophosphorylase, phosphocholine cytidylyltransferase, phosphorylcholine cytidylyltransferase, and phosphorylcholine:CTP cytidylyltransferase. This enzyme participates in aminophosphonate metabolism and glycerophospholipid metabolism.

References

BORKENHAGEN LF, KENNEDY EP (1957). "The enzymatic synthesis of cytidine diphosphate choline". J. Biol. Chem. 227 (2): 951–62. PMID 13463016.
KENNEDY EP, WEISS SB (1956). "The function of cytidine coenzymes in the biosynthesis of phospholipides". J. Biol. Chem. 222 (1): 193–214. PMID 13366993.
Williams-Ashman HG, Banks J (1956). "Participation of cytidine coenzymes in the metabolism of choline by seminal vesicles". J. Biol. Chem. 223 (1): 509–521. PMID 13376620.

Anabolism

to diacylglycerol: Acyltransferase Phosphatidate phosphatase 2C
Choline kinase CHKA CHKB Choline-phosphate cytidylyltransferase
phosphatidylinositol glycan anchor biosynthesis: PIGA PIGB PIGC PIGF PIGG PIGH PIGK PIGL PIGM PIGN PIGO PIGP PIGQ PIGS PIGT PIGU PIGV PIGW PIGX PIGY PIGZ
cardiolipin: Tafazzin

Catabolism

Phospholipase C
Diacylglycerol kinase DGKA DGKB DGKD DGKE DGKG DGKH DGKI DGKK DGKQ DGKZ
Phosphoric monoester hydrolases Inositol-phosphate phosphatase

Transferases: phosphorus-containing groups (EC 2.7)

2.7.1-2.7.4:
phosphotransferase/kinase
(PO₄)

2.7.1: OH acceptor	Hexo- Gluco- Fructo- Hepatic Galacto- Phosphofructo- 1 Liver Muscle Platelet 2 Riboflavin Shikimate Thymidine ADP-thymidine NAD⁺ Glycerol Pantothenate Mevalonate Pyruvate Deoxycytidine PFP Diacylglycerol Phosphoinositide 3 Class I PI 3 Class II PI 3 Sphingosine Glucose-1,6-bisphosphate synthase
2.7.2: COOH acceptor	Phosphoglycerate Aspartate kinase
2.7.3: N acceptor	Creatine
2.7.4: PO₄ acceptor	Phosphomevalonate Adenylate Nucleoside-diphosphate Uridylate Guanylate Thiamine-diphosphate

2.7.6: diphosphotransferase
(P₂O₇)

2.7.7: nucleotidyltransferase
(PO₄-nucleoside)

Polymerase

DNA polymerase	DNA-directed DNA polymerase I/A γ θ ν T7 Taq II/B α δ ε ζ Pfu III/C IV/X β λ μ TDT V/Y η ι κ RNA-directed DNA polymerase Reverse transcriptase Telomerase
RNA polymerase	Template-directed RNA polymerase I II III IV V ssRNAP POLRMT Primase 1 2 PrimPol RNA-dependent RNA polymerase Polyadenylation PAP PNPase

Phosphorolytic
3' to 5' exoribonuclease

Nucleotidyltransferase

Guanylyltransferase

mRNA capping enzyme

Other

2.7.8: miscellaneous

Phosphatidyltransferases	CDP-diacylglycerol—glycerol-3-phosphate 3-phosphatidyltransferase CDP-diacylglycerol—serine O-phosphatidyltransferase CDP-diacylglycerol—inositol 3-phosphatidyltransferase CDP-diacylglycerol—choline O-phosphatidyltransferase
Glycosyl-1-phosphotransferase	N-acetylglucosamine-1-phosphate transferase

2.7.10-2.7.13: protein kinase
(PO₄; protein acceptor)

2.7.10: protein-tyrosine	see tyrosine kinases
2.7.11: protein-serine/threonine	see serine/threonine-specific protein kinases
2.7.12: protein-dual-specificity	see serine/threonine-specific protein kinases
2.7.13: protein-histidine	Protein-histidine pros-kinase Protein-histidine tele-kinase Histidine kinase

v t e Enzymes
Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Diffusion-limited enzyme Cofactor Enzyme catalysis
Regulation	Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator
Classification	EC number Enzyme superfamily Enzyme family List of enzymes
Kinetics	Enzyme kinetics Eadie–Hofstee diagram Hanes–Woolf plot Lineweaver–Burk plot Michaelis–Menten kinetics
Types	EC1 Oxidoreductases (list) EC2 Transferases (list) EC3 Hydrolases (list) EC4 Lyases (list) EC5 Isomerases (list) EC6 Ligases (list) EC7 Translocases (list)

Structural studies

References