Class II gene transcription commences with the assembly of the Preinitiation Complex (PIC) from a plethora of proteins and protein assemblies in the nucleus, including the General Transcription Factors (GTFs), RNA polymerase II (RNA pol II), co-activators, co-repressors and more. TFIID, a megadalton-sized multiprotein complex comprising 20 subunits is among the first GTFs to bind the core promoter. TFIID assists in nucleating PIC formation, completed by binding of further factors in a highly regulated step-wise fashion. Recent results indicate that TFIID itself is built from distinct pre-formed submodules, which reside in the nucleus but also in the cytosol of cells. Here we highlight recent insights in transcription factor assembly and the regulation of transcription preinitiation.
Bibliographical noteSpecial Issue: Macromolecular Complexes in Transcription and Co-transcriptional RNA Processing
- Preinitiation complex (PIC)
- General Transcription Factor TFIID
- Transcription Initiation
- RNA polymerase II (RNA pol II)
- Multiprotein Complex
- Structural Biology