TFIIIC90 Inhibitors

Chemical inhibitors of TFIIIC90 are integral in regulating its function within the transcriptional machinery. Triptolide serves as one such inhibitor, directly impeding the assembly of the transcription factor III C (TFIIIC) complex, thereby inhibiting the activity of TFIIIC90. Another chemical, DrB (Dichlorobenzimidazole Riboside), targets RNA polymerase III activity, which is contingent on TFIIIC90 for the initiation of transcription at specific genes. This inhibition is critical as it prevents TFIIIC90 from fulfilling its role in the transcription initiation process. BMH-21 is known to bind to RNA polymerase I, leading to the enzyme's degradation. This action indirectly inhibits TFIIIC90 activity by reducing the overall pool of transcriptional resources, thus limiting RNA polymerase III interactions with TFIIIC90.

The chemical CX-5461 specifically inhibits RNA polymerase I transcription, which can limit the availability of transcription machinery for TFIIIC90's role in RNA polymerase III transcription. ML-60218 blocks the initiation step of RNA polymerase III transcription, where TFIIIC90 is essential for proper gene expression control. Further, H3B-8800 and Pladienolide B inhibit spliceosome-mediated splicing, which can indirectly limit the number of RNA targets that require TFIIIC90 for their transcription by RNA polymerase III. Similarly, spliceostatin A and Isoginkgetin target the spliceosome, thereby reducing the processing of RNA targets for TFIIIC90 and inhibiting its role in RNA polymerase III transcription. Meayamycin, another splicing inhibitor, affects the maturation of RNA transcripts that TFIIIC90 acts upon, thus indirectly inhibiting its function. Lastly, Madrasin disrupts splicing fidelity, which may decrease the pool of RNA transcripts necessitating TFIIIC90 for their transcription, further inhibiting the protein's activity within the cell. Each of these chemicals intervenes in cellular pathways and processes to inhibit the function of TFIIIC90, thereby regulating transcriptional activities where TFIIIC90 is normally a key component.