PRPF3 Inhibitors

Chemical inhibitors of PRPF3 target various aspects of the splicing machinery, a complex and essential cellular process for mRNA maturation, in which PRPF3 plays a crucial role. Pladienolide B, Meayamycin B, Madrasin, Spliceostatin A, and E7107 are notable for their precise action against the spliceosome complex. These compounds bind to different components of the splicing machinery, particularly affecting the SF3B complex. The binding of these chemicals to the spliceosome interferes with its proper assembly and function, leading to the disruption of RNA splicing. Since PRPF3 is integral to the spliceosome's operation, the action of these chemicals results in its functional inhibition. By destabilizing or altering the spliceosome complex, these inhibitors prevent PRPF3 from performing its role in the excision of introns and the ligation of exons, which are critical steps in generating mature RNA transcripts.

Isoginkgetin and Herboxidiene also inhibit the splicing process, but through a slightly different mechanism. Isoginkgetin obstructs spliceosome assembly, which precludes PRPF3 from being incorporated into the functional spliceosome. Herboxidiene, on the other hand, disrupts the spliceosome's function directly, which includes the activity of PRPF3. Placetin A and Placetin B extend the scope of inhibition to RNA polymerase II, an enzyme responsible for synthesizing precursor mRNA. By inhibiting RNA polymerase II, these chemicals limit the availability of precursor mRNA, essential for PRPF3 to act upon. Similarly, Tetrocarcin A acts upon RNA polymerase I, reducing the levels of rRNA precursor, thereby indirectly restraining the splicing activity that PRPF3 would typically carry out. Lastly, GEX1A compromises RNA polymerase II function, which again limits the pool of pre-mRNA for splicing, indirectly inhibiting PRPF3's activity in the process. Each of these chemicals, through their specific action on different components or phases of the RNA processing pathway, ensures the functional inhibition of PRPF3.