uridinetrifosfaat

Uridinetrifosfaat, usually abbreviated as UTP, is a ribonucleoside triphosphate composed of the nucleoside uridine attached to three phosphate groups. It is a high‑energy phosphate donor and an activated precursor involved in a variety of cellular processes. In many organisms, UTP sits alongside other nucleoside triphosphates as a key building block for RNA synthesis and nucleotide metabolism.

A central biological role of UTP is as a substrate for RNA synthesis. RNA polymerases use UTP, together with ATP, CTP and GTP, to assemble RNA strands during transcription. Beyond RNA production, UTP participates in metabolism through the formation of UDP‑sugars. Enzymes such as UDP‑sugar pyrophosphorylases catalyze the reaction of UTP with sugar‑1‑phosphate to form UDP‑sugars (for example UDP‑glucose) and inorganic pyrophosphate. UDP‑sugars serve as essential donors in the glycosylation of proteins and lipids.

Biosynthesis and turnover of UTP involve phosphorylation and interconversion with other nucleotides. UTP can be formed from UMP by kinases, and from UDP by nucleoside diphosphate kinases that transfer a phosphate from ATP. Cellular UTP levels are maintained in coordination with other nucleoside triphosphates and are subject to hydrolysis by pyrophosphatases.

In addition to intracellular roles, UTP also acts as an extracellular signaling molecule. It binds to purinergic P2Y receptors on various cell types, influencing processes such as ion transport, vascular tone, neurotransmission, and inflammation.

Overall, UTP is a multifunctional nucleotide involved in genetic information flow, carbohydrate activation, and signaling, reflecting its integral role in cellular physiology.