PWWP2A binds distinct chromatin moieties and interacts with an MTA1-specific core NuRD complex

Area of Science:

• Molecular Biology
• Epigenetics
• Chromatin Biology

Background:

• Reader proteins regulate chromatin structure and function by recognizing histone modifications and variants.
• PWWP2A was previously identified to bind H2A.Z nucleosomes and influence mitotic progression and development.

Purpose of the Study:

• To elucidate the detailed chromatin-binding properties of PWWP2A.
• To investigate the interaction of PWWP2A with the NuRD complex.
• To understand the functional role of PWWP2A in regulating histone acetylation.

Main Methods:

• In vitro binding assays to assess PWWP2A interactions with DNA and nucleosomes.
• In vivo chromatin immunoprecipitation (ChIP) to map PWWP2A binding sites.
• Depletion studies to analyze the effects of PWWP2A loss on histone acetylation and complex recruitment.

Main Results:

• PWWP2A binds to free linker DNA and H3K36me3 nucleosomes via distinct domains.
• In vivo, PWWP2A preferentially binds H2A.Z-containing regulatory regions over H3K36me3-containing gene bodies.
• PWWP2A interacts with an MTA1-specific subcomplex of NuRD (M1HR), excluding other NuRD components.
• PWWP2A depletion results in increased H3K27 and H2A.Z acetylation, linked to impaired M1HR chromatin recruitment.

Conclusions:

• PWWP2A is a multifaceted chromatin-binding protein.
• PWWP2A acts as a scaffold to recruit the M1HR deacetylase complex to H2A.Z-containing chromatin.
• This recruitment by PWWP2A is crucial for modulating histone acetylation levels.