MCM5 UFMylation regulates replication origin firing and fork progression.

Area of Science:

• Molecular Biology
• Genetics
• Cell Biology

Background:

• UFMylation is vital for cell proliferation, but its mechanism remains unclear.
• Mutations in UFMylation pathway genes are linked to microcephalic primordial dwarfism (MPD).
• MPD-associated mutations are found in DNA helicase complex components, including the MCM hexamer.

Purpose of the Study:

• To elucidate the role of UFMylation in DNA replication.
• To investigate the mechanistic link between UFMylation, DNA replication, and MPD disorders.

Main Methods:

• Investigated UFMylation's effect on DNA replication using MPD-associated mutants.
• Identified and characterized the UFMylation of MCM5 by the UFM1 E3 ligase UFL1.
• Analyzed the impact of Lys583 UFMylation on MCM5 and the CMG helicase complex stability.

Main Results:

• All tested MPD-associated mutations in UFMylation enzymes impaired DNA replication.
• UFL1 catalyzes Lys583 UFMylation of MCM5, a key part of the CMG helicase.
• Blocking Lys583 UFMylation destabilized the CMG complex, delaying origin firing and slowing replication fork progression.

Conclusions:

• MCM5 UFMylation is essential for efficient origin firing and replication fork progression.
• This process is critical for accurate DNA replication and cell proliferation.
• MCM5 UFMylation plays a role in preventing MPD disorders.