Rpp20 Inhibitors

Chemical inhibitors of Rpp20 can obstruct its role in RNA processing through various molecular mechanisms. Alloxan, for instance, generates oxidative stress that can selectively inhibit RNA processing enzymes. This oxidative environment can disrupt the molecular functionality of Rpp20, impeding its ability to properly process RNA. Similarly, Aurintricarboxylic Acid can hinder Rpp20's function by inhibiting nucleases that are essential for RNA maturation, thus preventing Rpp20 from performing its role in the RNA processing pathways. Ethidium Bromide, which intercalates into RNA, can inhibit Rpp20's RNA processing activities by blocking Rpp20's access to its RNA substrates.

In addition, Actinomycin D binds tightly to the DNA at the transcription initiation complex, stopping RNA polymerase in its tracks and thus preventing the elongation of RNA molecules that Rpp20 would typically process. α-Amanitin inhibits RNA polymerase II, leading to a reduction in mRNA synthesis and thereby limiting the functional role of Rpp20 due to a lack of RNA substrate. Leptomycin B, which inhibits the export of RNA from the nucleus, can also limit the availability of RNA molecules for Rpp20 to process in the cytoplasm. Ribavirin reduces guanosine triphosphate pools, which can influence guanosine-dependent RNA processing pathways and inhibit Rpp20's activity. Cordycepin acts as a chain terminator during RNA synthesis, resulting in premature termination and a subsequent reduction in mature RNA substrates for Rpp20 to process. Moreover, DRB blocks the phosphorylation of RNA polymerase II, which is essential for the transcription process, thereby decreasing the pool of RNA molecules for Rpp20. Lastly, Tunicamycin and Distamycin A, though not directly targeting Rpp20, can alter the cellular environment in ways that reduce the efficiency of RNA processing, indirectly affecting Rpp20's function. Tunicamycin does this by inhibiting glycosylation, while Distamycin A binds to DNA, affecting transcription factors and DNA-associated enzymes. Camptothecin's inhibition of DNA topoisomerase I leads to DNA damage that can affect transcription processes, thus indirectly inhibiting the function of Rpp20 by reducing the availability of RNA molecules for processing.