A Scalable Platform for Producing Recombinant Nucleosomes with Codified Histone Methyltransferase Substrate...

Area of Science:

• Biochemistry
• Molecular Biology
• Epigenetics

Background:

• Wolf-Hirschhorn Syndrome Candidate 1 (WHSC1), also known as NSD2, is a SET domain-containing histone lysine methyltransferase.
• Chromosomal translocations involving WHSC1 are found in 15-20% of multiple myeloma patients, correlating with increased WHSC1 production and poor prognosis.

Purpose of the Study:

• To define the substrate requirements of NSD2.
• To establish a robust platform for studying NSD2 activity on nucleosome substrates.

Main Methods:

• Developed a platform for large-scale production of recombinant polynucleosomes using authentic human histone proteins expressed in E. coli and complexed with linearized DNA.
• Validated the platform by assessing known methyltransferase activities.
• Investigated NSD2's methylation activity at histone 3 lysines 18 and 36.

Main Results:

• The platform successfully produced and characterized recombinant polynucleosomes.
• NSD2's primary activity on nucleosome substrates was identified as dimethylation of histone 3 lysine 36.
• Reaction mechanism studies indicated a processive, rather than distributive, mechanism for NSD2 interaction with nucleosomes.

Conclusions:

• The developed platform is suitable for studying NSD2 substrate requirements and reaction mechanisms.
• The findings provide insights into NSD2's enzymatic activity, relevant to multiple myeloma.
• The scalable and flexible methods are applicable to pharmaceutical-scale drug discovery campaigns targeting NSD2.