Dynamics and functional roles of splicing factor autoregulation.

Area of Science:

• Molecular Biology
• Gene Regulation
• Systems Biology

Background:

• Non-core spliceosome components regulate alternative splicing concentration-dependently.
• Splicing factors often autoregulate their own pre-mRNAs via negative feedback loops.
• The single-cell dynamics of these autoregulatory splicing feedback loops are not well understood.

Purpose of the Study:

• To quantitatively analyze the dynamics of negative autoregulatory splicing for splicing factor SRSF1 in single cells.
• To investigate the functional roles of SRSF1 negative autoregulation in gene expression and cellular homeostasis.
• To develop a mathematical model explaining the observed autoregulatory splicing features.

Main Methods:

• Developed a system for quantitative analysis of splicing factor SRSF1 negative autoregulatory splicing dynamics.
• Utilized single HEK293 cells and applied perturbations to study splicing responses.
• Constructed a minimal mathematical model to interpret experimental findings.

Main Results:

• Negative autoregulation establishes a ceiling for SRSF1 protein concentration.
• It reduces cell-to-cell heterogeneity in SRSF1 levels and buffers transcriptional variations.
• Autoregulation adapts SRSF1 splicing activity to changing demands from other pre-mRNA substrates.
• A mathematical model successfully explained these experimental observations.

Conclusions:

• Splicing negative autoregulation plays critical roles in homeostatic gene regulation.
• It contributes to stable protein levels, reduced heterogeneity, and adaptive splicing activity.
• These findings reveal the importance of autoregulation in maintaining robust transcriptional programs.