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SNM1B/Apollo interacts with astrin and is required for the prophase cell cycle checkpoint
Lingling Liu1, Shamima Akhter, Jae-Bum Bae
1Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.
Cell Cycle (Georgetown, Tex.)
|February 7, 2009
Summary
SNM1B/Apollo plays a new role in mitosis, enforcing the prophase checkpoint during spindle stress. Its interaction with Astrin is crucial for this function, preventing extended mitotic delays.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- SNM1A is involved in DNA damage response and mitotic checkpoints.
- SNM1B/Apollo (Apollo) has roles in DNA interstrand cross-linking response and telomere protection.
- The function of SNM1B/Apollo in mitosis under spindle stress is not well understood.
Purpose of the Study:
- To investigate the role of SNM1B/Apollo in mitosis during spindle stress.
- To identify novel interactions and functions of SNM1B/Apollo in cell division.
- To elucidate the mechanism by which SNM1B/Apollo regulates the mitotic checkpoint.
Main Methods:
- Studied SNM1B-deficient cells to assess mitotic progression.
- Analyzed checkpoint activation and mitotic delay.
- Investigated protein-protein interactions between SNM1B/Apollo and Astrin using mutation analysis.
Main Results:
- SNM1B-deficient cells show a defect in the prophase checkpoint.
- Loss of the prophase checkpoint leads to prolonged mitotic delay due to sustained spindle checkpoint activation.
- SNM1B/Apollo interacts with the microtubule-binding protein Astrin via its metallo-beta-lactamase domain.
- Disrupting the SNM1B/Apollo-Astrin interaction impairs the prophase checkpoint.
Conclusions:
- SNM1B/Apollo has a novel role in enforcing the prophase checkpoint in response to spindle stress.
- SNM1B/Apollo and Astrin collaborate to maintain the integrity of the prophase checkpoint.
- This interaction is critical for preventing prolonged mitotic delays and ensuring proper cell division.
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