NUDT5 restrains PPAT to promote pyrimidine synthesis and effective nucleobase therapy - NUDT5 co-immunoprecipitation

ABSTRACT: Nucleotides are essential building blocks for nucleic acid synthesis, signaling, and metabolism. Rapidly proliferating cells require large amounts of nucleotides, making nucleotide metabolism a widely exploited target for cancer therapy. However, resistance frequently emerges, highlighting the need for a deeper understanding of nucleotide regulation. Here, we use uridine-sensitized CRISPR-Cas9 screening to reveal novel regulators of pyrimidine synthesis. We identify NUDT5 which we show binds to and negatively regulates PPAT, the rate-limiting enzyme in purine biosynthesis. We demonstrate the NUDT5-PPAT interaction prevents excessive purine production, maintains phosphoribosyl pyrophosphate (PRPP), a critical substrate for pyrimidine synthesis, and thus enhances conversion of nucleobase analogs into active anti-cancer molecules. We further report that NUDT5 regulates PPAT independently of its enzymatic activity and can be displaced by PRPP, revealing intricate allosteric regulation. Our findings reveal a previously unrecognized mechanism for maintaining nucleotide balance and positions NUDT5 as a potential therapeutic target for overcoming resistance to chemotherapy in proliferative diseases.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

SUBMITTER: Alexis Jourdain  

LAB HEAD: Alexis Jourdain

PROVIDER: PXD060353 | Pride | 2025-10-29

REPOSITORIES: Pride