4-Thio-Uridine nucleotides without substituents on the Sulphur atom are used for photochemical UV-crosslinking studies of RNA. Furthermore, they show altered hybridization properties compared to unmodified Uridine: 4-Thio-Uridine hybridizes to Guanosine instead of Adenosine.
Chemically modified pyrimidine nucleotides like 4-substituted pyrimidine nucleotide analogs are furthermore potential agonists of P2Y receptors for pharmacological studies.
The family of P2Y nucleotide receptors are important therapeutic targets including antithrombotic therapy, modulation of the immune system and cardiovascular system, inflammation, pain, diabetes, and treatment of cystic fibrosis and other pulmonary diseases. P2Y receptors are activated by adenine and/or uracil nucleotides.