Uridine-5′-triphosphate (UTP) is a pyrimidine

nucleoside triphosphate A nucleoside triphosphate is a nucleoside containing a nitrogenous base bound to a 5-carbon sugar (either ribose or deoxyribose), with three phosphate groups bound to the sugar. They are the molecular precursors of both DNA and RNA, which are ch ...

, consisting of the

organic base An organic base is an organic compound which acts as a base. Organic bases are usually, but not always, proton acceptors. They usually contain nitrogen atoms, which can easily be protonated. For example, amines or nitrogen-containing heterocyclic ...

uracil Uracil () (symbol U or Ura) is one of the four nucleobases in the nucleic acid RNA. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced b ...

linked to the 1′ carbon of the

ribose Ribose is a simple sugar and carbohydrate with molecular formula C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H. The naturally-occurring form, , is a component of the ribonucleotides from which RNA is built, and so this compo ...

sugar, and esterified with tri-

phosphoric acid Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, w ...

at the 5′ position. Its main role is as substrate for the synthesis of RNA during

transcription Transcription refers to the process of converting sounds (voice, music etc.) into letters or musical notes, or producing a copy of something in another medium, including: Genetics * Transcription (biology), the copying of DNA into RNA, the fir ...

. UTP is the precursor for the production of CTP via the help of CTP Synthetase. UTP can be biosynthesized from UDP by Nucleoside Diphosphate Kinase after using phosphate group from ATP. UDP + ATP ⇌ UTP + ADP; both UTP and ATP are energetically equal. The homologue in DNA is thymidine triphosphate (TTP or dTTP). UTP also has a deoxyribose form (dUTP).

Role in metabolism

UTP also has the role of a source of energy or an activator of substrates in metabolic reactions, like that of ATP, but more specific. When UTP activates a substrate (like Glucose-1-phosphate), UDP-glucose is formed and inorganic phosphate is released.

UDP-glucose Uridine diphosphate glucose (uracil-diphosphate glucose, UDP-glucose) is a nucleotide sugar. It is involved in glycosyltransferase reactions in metabolism. Functions UDP-glucose is used in nucleotide sugar metabolism as an activated form of gl ...

enters the synthesis of glycogen. UTP is used in the metabolism of

galactose Galactose (, '' galacto-'' + ''-ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecu ...

, where the activated form

UDP-galactose Uridine diphosphate galactose ( UDP- galactose) is an intermediate in the production of polysaccharides. It is important in nucleotide sugars metabolism, and is the substrate for the transferase B4GALT5. See also * Galactose * UDP galactose e ...

is converted to UDP-glucose. UDP-glucuronate is used to conjugate bilirubin to a more water-soluble

bilirubin diglucuronide Bilirubin di-glucuronide is a conjugated form of bilirubin formed in bilirubin metabolism. The hydrophilic character of bilirubin diglucuronide enables it to be water-soluble. It is pumped across the hepatic canalicular membrane into the bile by th ...

. UTP is also used to activate amino sugars like Glucosamine-1-phosphate to UDP-glucosamine, and N-acetyl-glucosamine-1-phosphate to UDP-N-acetylglucosamine.

Role in receptor mediation

UTP also has roles in mediating responses by extracellular binding to the P2Y receptors of cells. UTP and its derivatives are still being investigated for their applications in human medicine.

References

Nucleotides Gene expression Metabolism Phosphate esters Pyrimidinediones {{Biochem-stub