USP6

Uridine phosphorylase 1 (UPP1) is an enzyme that in humans is encoded by the UPP1 gene. This enzyme is involved in the pyrimidine salvage pathway, which is crucial for the recycling of nucleotides. UPP1 catalyzes the reversible phosphorolysis of uridine to uracil and ribose-1-phosphate.

Function

UPP1 plays a significant role in the pyrimidine salvage pathway, which is essential for maintaining the nucleotide pool balance within the cell. The enzyme catalyzes the conversion of uridine, a nucleoside, into uracil, a pyrimidine base, and ribose-1-phosphate. This reaction is reversible and allows cells to efficiently recycle nucleotides, which is particularly important in tissues with high turnover rates, such as the liver and bone marrow.

Structure

The UPP1 enzyme is a homodimer, meaning it consists of two identical subunits. Each subunit binds to a molecule of uridine and a phosphate ion, facilitating the phosphorolysis reaction. The active site of UPP1 is highly conserved and is responsible for the enzyme's specificity for uridine.

Clinical Significance

Alterations in UPP1 activity have been associated with various pathological conditions. Overexpression of UPP1 has been observed in certain types of cancer, where it may contribute to the increased nucleotide demand of rapidly proliferating tumor cells. Conversely, deficiencies in UPP1 activity can lead to imbalances in nucleotide pools, potentially resulting in metabolic disorders.

Genetic Information

The UPP1 gene is located on chromosome 7 at the p12 band. It consists of multiple exons and is subject to regulation by various transcription factors. Mutations in the UPP1 gene can affect enzyme activity and have been studied in the context of genetic disorders involving nucleotide metabolism.

Research and Applications

Research into UPP1 has implications for cancer therapy, as inhibitors of this enzyme could potentially disrupt the nucleotide supply to tumor cells, thereby inhibiting their growth. Additionally, understanding the regulation of UPP1 could lead to novel treatments for metabolic disorders involving pyrimidine metabolism.

Also see

• Pyrimidine metabolism
• Nucleotide salvage pathway
• Uridine
• Uracil
• Ribose-1-phosphate