PARP1 Regulates Circular RNA Biogenesis though Control of Transcriptional Dynamics

Area of Science:

• Molecular Biology
• RNA Biology
• Gene Regulation

Background:

• Circular RNAs (circRNAs) are key regulators of gene expression with emerging biological and pathological significance.
• The precise mechanisms governing circRNA formation via backsplicing remain incompletely understood.
• Poly (ADP-ribose) polymerase I (PARP1) is known to modulate alternative splicing, but its role in circRNA biogenesis is unexplored.

Purpose of the Study:

• To investigate the potential role of PARP1 in the regulation of circRNA biogenesis.
• To elucidate how PARP1 activity and gene architecture influence circRNA production.

Main Methods:

• Analysis of circRNA profiles in conditions of PARP1 depletion and PARylation inhibition.
• Comparative analysis of gene architecture, including intron length, in circRNA host genes.
• Investigation of PARP1's regulation of RNA polymerase II (RNAPII) pausing in relation to gene structure.

Main Results:

• PARP1 modulation significantly alters circRNA profiles compared to wild-type.
• Host genes producing circRNAs under PARP1 knockdown exhibit distinct intron asymmetry (longer upstream introns).
• PARP1 regulates RNAPII pausing differently based on host gene architecture, impacting circRNA biogenesis.

Conclusions:

• PARP1 plays a crucial role in regulating circRNA biogenesis.
• PARP1-mediated RNAPII pausing, in conjunction with gene architecture, controls transcriptional kinetics for circRNA formation.
• This regulatory pathway fine-tunes gene expression with potential implications for cellular function.