Novel CRK-Cyclin Complex Controls Spindle Assembly Checkpoint in Toxoplasma Endodyogeny.
Lauren M Hawkins1, Anatoli V Naumov1, Mrinalini Batra1
1Division of Infectious Diseases, Department of Internal Medicine, Morsani College of Medicine, University of South Floridagrid.170693.a, Tampa, Florida, USA.
Mbio
|February 8, 2022
Summary
Researchers discovered a new protein complex, TgCrk6/TgCyc1, crucial for regulating cell division in Toxoplasma gondii. This complex controls a key mitotic event, the spindle assembly checkpoint, offering potential targets for controlling toxoplasmosis.
Area of Science:
- Cell Biology
- Parasitology
- Molecular Biology
Background:
- Apicomplexa parasites exhibit unique cell cycle and mitosis mechanisms.
- Understanding these mechanisms is vital for controlling diseases like toxoplasmosis.
Purpose of the Study:
- To investigate the role of atypical Cdk-related kinase TgCrk6 in Toxoplasma gondii cell division.
- To identify and characterize novel factors regulating parasite mitosis.
Main Methods:
- Genetics
- Quantitative fluorescence microscopy
- Global proteomics
- Conditional expression models
Main Results:
- Identified a novel parasite-specific complex, TgCrk6/TgCyc1.
- TgCrk6/TgCyc1 regulates metaphase and the spindle assembly checkpoint (SAC) in T. gondii.
- Parasite-specific tasks are integrated into the canonical SAC functions.
Conclusions:
- The TgCrk6/TgCyc1 complex is essential for T. gondii mitosis.
- This complex offers a potential target for therapeutic intervention against toxoplasmosis.
Related Concept Videos
02:19The Spindle Assembly Checkpoint
3.3K
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
3.3K
00:50Anaphase Promoting Complex
3.0K
The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
3.0K
02:15M-Cdk Drives Transition Into Mitosis
5.7K
Checkpoints throughout the cell cycle serve as safeguards and gatekeepers, allowing the cell cycle to progress in favorable conditions and slow or halt it in problematic ones. This regulation is known as the cell cycle control system.
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
5.7K
02:17Separation of Sister Chromatids
3.8K
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
3.8K
01:28The Cell Cycle Control System
3.7K
The cell cycle regulation directs how a cell proceeds from one phase to the next and begins mitosis. The cell cycle control system includes intracellular regulatory molecules and external triggers. They provide "stop" or "advance" signals and operate at specific cell cycle stages termed checkpoints to ensure that a particular process is completed before the cell advances to the next phase.
Cyclins and cyclin-dependent kinases (Cdks) are the primary cell cycle regulators and...
Cyclins and cyclin-dependent kinases (Cdks) are the primary cell cycle regulators and...
3.7K
02:39Positive Regulator Molecules
5.7K
Mitotic cell division results in daughter cells that exactly resemble the parent cell. However, errors in the DNA replication or distribution of genetic material may lead to genetic mutations that may be passed down to every new cell formed from the resulting abnormal cell. Propagation of such mutant cells is restricted through checkpoint mechanisms present at different stages of the cell cycle. These checkpoints involve regulator molecules that either promote or demote cell cycle events.
5.7K