KärnTFIIH

KärnTFIIH, also known as the core transcription factor IIH, is a protein complex that plays a crucial role in the regulation of gene transcription. It is a component of the general transcription factor TFIIH, which is essential for the initiation of RNA polymerase II-dependent transcription. TFIIH is a large protein complex that consists of several subunits, including the core subunits (TFIIHc) and the regulatory subunits (TFIIHr). KärnTFIIH specifically refers to the core subunits of TFIIH, which include XPD, XPG, CSB, and ERCC6.

The core subunits of TFIIH have distinct functions in the transcription process. XPD and XPG are DNA helicases that unwind the DNA double helix to create a transcription bubble, allowing RNA polymerase II to access the DNA template. CSB is a clamp loader that loads the PCNA (proliferating cell nuclear antigen) clamp onto the DNA, which stabilizes the transcription bubble and facilitates the processive movement of RNA polymerase II. ERCC6 is a DNA helicase that is involved in the repair of UV-damaged DNA, and it also plays a role in transcription by facilitating the unwinding of the DNA helix.

KärnTFIIH is regulated by various post-translational modifications, including phosphorylation and ubiquitination, which modulate its activity and stability. Dysregulation of TFIIH, including its core subunits, has been implicated in several diseases, such as cancer and neurodegenerative disorders. Therefore, understanding the molecular mechanisms underlying the regulation of TFIIH and its core subunits is of great importance for the development of new therapeutic strategies for these diseases.