Effect of depletion of IMPDH1 and IMPDH2 on gene expression after DNA damage in HeLa cells

Guanosine nucleotide (GTP) serves as a pivotal purine nucleoside triphosphate, essential for DNA and RNA structure and function. Additionally, it acts as an activator for the guanine-binding protein family (G protein), participating in crucial cellular processes such as cytoskeleton rearrangement, membrane transport, protein synthesis, and signal transduction. IMPDH1 and IMPDH2 are key enzymes in the de novo synthesis of guanine nucleotides. Our research shows that they exhibit differential activities under DNA damage conditions. Specifically, IMPDH1 predominantly maintains enzymatic activity during DNA damage, facilitating GTP synthesis and cell survival. Our data indicate that following DNA damage, IMPDH1 and IMPDH2 affect distinct pathways in cells, with IMPDH1 potentially promoting the expression of homologous recombination repair proteins. Overall design: To investigate the distinct impacts of IMPDH1 and IMPDH2 on gene expression following DNA damage, we generated stable knockdown cell lines for both IMPDH1 and IMPDH2. Subsequently, we treated wild-type (WT), IMPDH1 knockdown (KD), and IMPDH2 KD cells with the DNA damage-inducing drug TMZ. After treatment, we harvested the cells for RNA sequencing and conducted gene expression analysis based on the RNA sequencing results.