Arginine Methylation Antagonizes TEAD3-Mediated Repression to Promote Osteogenic Differentiation by Disrupting...

Area of Science:

• Molecular Biology
• Stem Cell Biology
• Biochemistry

Background:

• Osteogenic differentiation is crucial for bone remodeling and repair processes.
• Protein arginine methyltransferases (PRMTs) are known regulators of osteogenesis, but their specific substrates and mechanisms are not fully understood.
• Periodontal ligament stem cells (PDLSCs) are key players in periodontal tissue regeneration.

Purpose of the Study:

• To identify novel arginine-methylated regulators involved in PDLSC osteogenesis.
• To elucidate the mechanism by which these regulators control the osteogenic differentiation process.
• To explore potential therapeutic strategies targeting these regulators for bone regeneration.

Main Methods:

• Identification of TEAD3 as an arginine-methylated protein in PDLSCs.
• Site-directed mutagenesis to disrupt arginine 55 (R55) methylation in TEAD3.
• Analysis of TEAD3 homodimer condensate formation and RUNX2 transcriptional activity.
• Assessment of TEAD3-R55K mutant sensitivity to TEA domain inhibitory peptide (TEAi).

Main Results:

• TEAD3, a transcription factor mediating Hippo signaling, was identified as an arginine-methylated regulator of PDLSC osteogenesis.
• Methylation occurs at R55 within TEAD3's DNA-binding domain.
• Disruption of R55 methylation (R55K mutation) enhanced TEAD3 homodimer condensate formation, spatially constraining RUNX2 activity.
• The TEAD3-R55K mutant showed increased sensitivity to TEAi, a peptide inhibitor targeting the TEA domain.

Conclusions:

• Arginine methylation of TEAD3 acts as a critical switch governing osteogenic commitment.
• Modulating TEAD3 methylation impacts stem cell differentiation and bone formation.
• TEAD-targeted strategies, particularly using inhibitors like TEAi, show promise for enhancing bone regeneration therapies.