RNA polymerase II CTD modifications: how many tales from a single tail

Area of Science:

• Molecular Biology
• Biochemistry
• Genetics

Background:

• Eukaryotic RNA polymerase II (RNAPII) possesses a unique C-terminal domain (CTD) in its largest subunit, Rpb1.
• The Rpb1-CTD consists of repeating heptad units (Y1S2P3T4S5P6S7) whose number varies with organismal development.
• The CTD's structural plasticity allows extensive post-translational modifications and proline cis/trans isomerization, influencing its function.

Purpose of the Study:

• To review recent literature on the Rpb1-CTD.
• To provide an overview of the Rpb1-CTD's general function in transcription.
• To highlight the CTD's roles in co-transcriptional and non-transcriptional processes.

Main Methods:

• Literature review of recent CTD-related studies.

Main Results:

• CTD modifications and interacting factors are specific to gene promoters and transcription cycle stages.
• The CTD regulates not only transcription rates but also co-transcriptional events like pre-mRNA processing, splicing, cleavage, and export.
• Emerging evidence links specific CTD modifications to DNA replication and genomic stability maintenance.

Conclusions:

• The Rpb1-CTD is a critical regulator with diverse functions extending beyond transcription.
• CTD modifications play key roles in various cellular processes, including DNA replication and genomic stability.
• Further research into CTD modifications will elucidate its multifaceted roles in eukaryotic cell biology.