Sox2 uses multiple domains to associate with proteins present in Sox2-protein complexes

Area of Science:

• Stem cell biology
• Molecular and cellular biology
• Epigenetics

Background:

• Master regulators, including Sox2, Oct4, and Nanog, are crucial for embryonic stem cell (ESC) self-renewal and pluripotency.
• These regulators orchestrate gene expression through interactions with co-activators and co-repressors.
• Proteomic studies have identified numerous co-factors associated with master regulators like Sox2.

Purpose of the Study:

• To investigate the size distribution of nuclear protein complexes involving Sox2 and its partners (HDAC1, Sall4, Lin28).
• To identify the specific domains of Sox2 responsible for its interactions with partner proteins (Sall4, HDAC1, HDAC2) and self-association.

Main Methods:

• Analysis of nuclear protein complex size distribution using techniques like size-exclusion chromatography (implied).
• Domain mapping studies to determine regions of Sox2 involved in protein-protein interactions and self-association.

Main Results:

• Sox2 and HDAC1 associate with protein complexes of widely varying sizes.
• Lin28 predominantly binds to smaller complexes, while Sall4 associates with larger complexes.
• Sox2 utilizes multiple distinct domains for binding to Sall4, HDAC1, HDAC2, and for self-association.

Conclusions:

• Sox2 exhibits flexible interaction dynamics, associating with diverse protein complex sizes.
• Multiple domains within Sox2 mediate its interactions with various partners and self-association.
• These findings offer new insights into the mechanisms by which Sox2 regulates gene transcription through complex formation.