Journal of Biomedical Science, Год журнала: 2025, Номер 32(1)
Опубликована: Апрель 4, 2025
Abstract Background Phosphorylation and O-GlcNAcylation are the key modifications regulating RNA Polymerase II (RNA Pol II)-driven transcription. Transcriptional kinases, cyclin-dependent kinase 7 (CDK7), CDK9 CDK12 phosphorylate II, whereas is added by O-GlcNAc transferase (OGT) removed O-GlcNAcase (OGA). Currently, no study has systematically evaluated how inhibiting each of these enzyme activities impacts assembly appropriate protein complexes on polymerase maturation mRNA. Methods Here, we evaluate remodeling interactome effects nascent mRNA using mass spectrometry SLAM-seq, respectively. For validation, rely predominantly analysis intronic polyadenylation (IPA) sites, mitochondrial flux assays (Seahorse), western blotting patient data. Results We show that OGT / OGA inhibition reciprocally affect recruitment to levels required for optimal function complex. These paradoxical explained through IPA, because despite being prematurely poly-adenylated, mRNAs scored as mature in SLAM-seq. Unlike previously proposed, that, similar CDK12, also targeting stimulates transcription short genes at cost long genes. However, our systematic proteomic- IPA-analysis revealed mediated distinct molecular mechanisms: leads a failure recruiting Integrator complex then depletion subunits phenocopy gene length-dependent effects. In contrast, triggers IPA. Finally, dynamic interplays with CDK9: augments inhibitor due defects elongation, while rescues caused CDK9, but induces Conclusion negative regulator biosynthesis propose addition removal modification serve quality control-steps ascertain successful generation mRNAs. Our work identifies unprecedented redundancy regulation which increases resilience towards transcriptional stress, underscores difficulty control cancer. Graphical
Язык: Английский