The UFM1 cascade times mitosis entry associated with microcephaly
Li Yu1,2, Guangxu Li1,2, Jing Deng1,2
1Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China.
Summary
The UFM1 cascade is crucial for brain development, as its disruption causes microcephaly by impairing cell division and mitotic progression in neuroblasts.
Area of Science:
- Cell Biology
- Developmental Biology
- Genetics
Background:
- Posttranslational modifications, like ufmylation, diversify proteome function.
- The UFM1 cascade, a ubiquitin-like modification system, is implicated in microcephaly.
- Pathological mechanisms linking UFM1 mutations to microcephaly are not fully understood.
Purpose of the Study:
- To investigate the role of the UFM1 cascade in neurodevelopment and cell cycle regulation.
- To elucidate the pathological mechanisms underlying UFM1-associated microcephaly.
Main Methods:
- Disruption of the UFM1 cascade in Drosophila neuroblasts and embryos.
- Live imaging of embryonic development.
- Analysis of mitotic progression, centrosome, microtubule, and DNA integrity.
- Assessment of CDK1 phosphorylation levels.
Main Results:
- Disruption of the UFM1 cascade in Drosophila neuroblasts reduced neuroblast numbers and brain size.
- Lack of ufmylation led to increased mitotic index and extended G2/M phase, indicating defective mitotic progression.
- Impaired Ufl1 function caused premature mitotic entry, failed cellularization, and embryonic lethality.
- Observed phenotypes included detached centrosomes, defective microtubules, and DNA bridges.
- The UFM1 cascade regulates CDK1 phosphorylation at tyrosine-15, a key cell cycle regulator.
Conclusions:
- The UFM1 cascade is essential for proper neuroblast proliferation and mitotic progression.
- Defects in the UFM1 cascade contribute to microcephaly by disrupting cell cycle control.
- UFM1 cascade dysfunction impacts key mitotic events, including centrosome stability and microtubule dynamics.
