Biomedical subjects

Bin Peng

Publications and source records attributed to Bin Peng.

3 recordsLinked to original sources

PubMed2025

MCM5 UFMylation regulates replication origin firing and fork progression.

Modification with UFM1 (UFMylation) is essential for cell proliferation, but its precise mechanism of action is unclear. Furthermore, the UFMylation pathway has been associated with microcephalic primordial dwarfism (MPD) disorders, and mutations causative for MPD are also identified in genes encoding components of the replicative DNA helicase complex, including the MCM hexamer. Here, we reveal that UFMylation regulates DNA replication, and that all MPD-associated mutations in UFMylation enzymes impair replication. Mechanistically, the UFM1 E3 ligase UFL1 catalyzes Lys583 UFMylation of MCM5, a critical component of the CMG replicative DNA helicase complex. Mutation of Lys583 blocking this UFMylation event destabilizes the helicase complex, delaying origin firing and slowing replication fork progression. We conclude that MCM5 UFMylation is essential for efficient origin firing and replication fork progression, both of which ensure accurate DNA replication, cell proliferation, and prevention of MPD disorders.

DNA Replication↗

PubMed2025

The Role of Polo-Like Kinase 1 (PLK1) O-GlcNAcylation in Mitosis.

Polo-like kinase 1 (PLK1) is a crucial mitotic kinase that is implicated in various aspects of cell cycle. Many post-translational modifications have been identified on PLK1 to regulate its activation, stability, and localization. PLK1 has been shown previously to colocalize with the O-linked β-N-acetylglucosamine (O-GlcNAc) transferase (OGT), and OGT regulates PLK1 stability. In our recent work, we show that PLK1 is O-GlcNAcylated by click chemistry. Using stepped collisional energy/higher energy collision dissociation mass spectrometry, we mapped the PLK1 O-GlcNAc site to be T291. We further utilized fluorescent activated cell sorting and time-lapse microscopy to assess the mitotic defects of PLK1 O-GlcNAc mutants. In vivo studies in mouse xenograft demonstrated that it promoted uterine cancer tumorigenesis. In this chapter, we delineate the methodologies we used in studying PLK1 O-GlcNAcylation, including click chemistry, stepped collisional energy/higher energy collision dissociation mass spectrometry, fluorescent activated cell sorting, time-lapse microscopy, and mouse xenograft assays.

Polo-Like Kinase 1↗

PubMed2024

PARP1 UFMylation ensures the stability of stalled replication forks.

The S-phase checkpoint involving CHK1 is essential for fork stability in response to fork stalling. PARP1 acts as a sensor of replication stress and is required for CHK1 activation. However, it is unclear how the activity of PARP1 is regulated. Here, we found that UFMylation is required for the efficient activation of CHK1 by UFMylating PARP1 at K548 during replication stress. Inactivation of UFL1, the E3 enzyme essential for UFMylation, delayed CHK1 activation and inhibits nascent DNA degradation during replication blockage as seen in PARP1-deficient cells. An in vitro study indicated that PARP1 is UFMylated at K548, which enhances its catalytic activity. Correspondingly, a PARP1 UFMylation-deficient mutant (K548R) and pathogenic mutant (F553L) compromised CHK1 activation, the restart of stalled replication forks following replication blockage, and chromosome stability. Defective PARP1 UFMylation also resulted in excessive nascent DNA degradation at stalled replication forks. Finally, we observed that PARP1 UFMylation-deficient knock-in mice exhibited increased sensitivity to replication stress caused by anticancer treatments. Thus, we demonstrate that PARP1 UFMylation promotes CHK1 activation and replication fork stability during replication stress, thus safeguarding genome integrity.

DNA Replication↗