HuR thermal stability is dependent on domain binding and upon phosphorylation.

Area of Science:

• Molecular Biology
• Biochemistry
• RNA Biology

Background:

• Human Antigen R (HuR) is a key RNA-binding protein regulating mRNA stability and translation.
• HuR's function is modulated by its modular structure, including RNA recognition motifs (RRMs), and phosphorylation.
• Posttranscriptional regulation by HuR impacts gene expression.

Purpose of the Study:

• To investigate the structural and functional interplay between HuR's RNA recognition motifs (RRMs).
• To explore the impact of phosphorylation on HuR's stability and RNA-binding activity.

Main Methods:

• Thermal stability assays were used to assess the interaction between HuR's RRM1 and RRM2 domains.
• Analysis of HuR mutants mimicking phosphorylation was performed to evaluate structural and stability changes.

Main Results:

• The presence of RRM1 decreases the thermal stability of RRM2, suggesting domain interaction.
• Phosphorylation-mimicking mutants showed subtle stability differences, not significant structural changes.
• These stability variations may correlate with HuR's RNA binding capabilities.

Conclusions:

• HuR domains (RRM1 and RRM2) interact in solution, influencing protein stability.
• Phosphorylation may subtly affect HuR stability, potentially modulating its RNA binding activity.
• Understanding HuR domain interactions and phosphorylation is crucial for posttranscriptional regulation insights.