Poly(ADP-ribose) binding and macroH2A mediate recruitment and functions of KDM5A at DNA lesions

Area of Science:

• Epigenetics and Chromatin Biology
• DNA Damage Response (DDR)
• Molecular Mechanisms of Gene Regulation

Background:

• KDM5A is a histone demethylase that removes H3K4 methylation, impacting transcription and DNA damage responses.
• The precise mechanisms by which KDM5A localizes to DNA lesion sites within chromatin remain poorly understood.
• Understanding KDM5A's recruitment to DNA breaks is critical for elucidating its role in maintaining genome integrity.

Purpose of the Study:

• To identify factors and mechanisms governing KDM5A recruitment to DNA damage sites.
• To elucidate the role of poly(ADP-ribose) (PAR) and histone variants in KDM5A's DNA damage response functions.
• To understand how KDM5A's interaction with DNA lesions influences transcriptional regulation and repair processes.

Main Methods:

• Identification of a unique noncanonical poly(ADP-ribose) (PAR)-binding region in KDM5A.
• Assessment of KDM5A-PAR interactions and DNA repair functions following disruption of the PAR-binding region or PARP inhibitor treatment.
• Investigation of the requirement for histone variant macroH2A1.2 in KDM5A recruitment and function at DNA damage sites.

Main Results:

• A novel PAR-binding region in KDM5A was identified, essential for its interaction with PAR.
• Disruption of the PAR-binding region or PARP inhibition abrogated KDM5A-PAR interactions and its DNA repair capabilities.
• The histone variant macroH2A1.2 was found to be specifically required for KDM5A recruitment and function, including homology-directed repair and transcriptional repression at DNA breaks.

Conclusions:

• PAR binding and the histone variant macroH2A1.2 are critical for KDM5A's recognition of DNA lesion sites.
• These interactions facilitate KDM5A's roles in transcriptional regulation and DNA repair at sites of DNA breaks.
• The study reveals key molecular players essential for KDM5A's function in maintaining genome integrity.