PRC1 and PRC2 proximal interactome in mouse embryonic stem cells.

Area of Science:

• Developmental Biology
• Epigenetics
• Molecular Biology

Background:

• Polycomb repressive complexes (PRC1 and PRC2) are crucial for lineage-specific gene silencing during early embryogenesis.
• Understanding the molecular interactions of PRC1 and PRC2 is key to deciphering their roles in development and gene regulation.

Purpose of the Study:

• To profile the proximal interactome (proxeome) of PRC1 and PRC2 subunits in mouse embryonic stem cells (mESCs).
• To identify novel protein partners and understand the functional relationships between PRC1 and PRC2.
• To investigate the dynamic interactions of PRC2 in different cellular contexts during early development.

Main Methods:

• Proteomic profiling of PRC1 and PRC2 proximal interactomes in mESCs.
• Identification and analysis of co-localizing proteins, including transcription factors and RNA-binding proteins.
• Comparative analysis of PRC2 proxeomes across distinct mESC states and embryoid bodies.

Main Results:

• Identification of over 100 proteins proximal to PRC1 and PRC2, including pluripotency factors like NANOG.
• Significant overlap between PRC1 and PRC2 interactors, suggesting cooperative functions.
• PRC1 members were found in PRC2 proxeomes, but not vice versa, indicating potential independent functions.
• NANOG colocalizes with PRC2 and relocalizes upon PRC2 disruption.
• PRC2 interactomes vary across different mESC culture conditions and developmental stages.

Conclusions:

• The study provides a comprehensive resource for understanding Polycomb biology and the complex interplay of PRC1 and PRC2.
• Findings suggest both cooperative and independent roles for PRC1 and PRC2 in gene silencing and developmental regulation.
• The dynamic nature of PRC2 interactions highlights its adaptability across different cellular and developmental contexts.