Related Experiment Video
Updated: Jul 15, 2025
08:57
Aip1p Dynamics Are Altered by the R256H Mutation in Actin
Published on: July 30, 2014
8.0K
CEP104/FAP256 and associated cap complex maintain stability of the ciliary tip.
Thibault Legal1, Mireya Parra2, Maxwell Tong1
1Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, McGill University, Québec, Canada.
The Journal of Cell Biology
|September 27, 2023
Summary
Researchers revealed the intricate structure of ciliary tips using cryo-electron tomography. They identified key proteins stabilizing the tip and regulating cilium assembly and length.
Area of Science:
- Cell Biology
- Structural Biology
- Biochemistry
Background:
- Cilia are vital organelles with a microtubule-based axoneme.
- The ciliary tip structure is distinct and crucial for function.
- Understanding ciliary tip assembly and regulation is key to cell biology.
Purpose of the Study:
- To determine the high-resolution structure of the ciliary tip in Tetrahymena thermophila.
- To identify proteins involved in ciliary tip stabilization and function.
- To elucidate the role of CEP104/FAP256 in ciliary assembly and length regulation.
Main Methods:
- Cryo-electron tomography (cryo-ET) for high-resolution imaging.
- Subtomogram averaging to reconstruct the ciliary tip structure.
- Proteomics to identify protein components and analyze mutant cells.
Main Results:
- Detailed structure of the Tetrahymena thermophila ciliary tip revealed.
- Microtubules are crosslinked and stabilized by luminal proteins, plugs, and cap proteins.
- The central pair structure is unique, lacking projections and exhibiting significant twisting.
- CEP104/FAP256 is identified as a component of the central pair cap complex, influencing ciliary assembly.
Conclusions:
- The ciliary tip possesses a unique, stabilized structure essential for its function.
- CEP104/FAP256 plays a critical role in regulating ciliary tip formation and overall cilium length.
- These findings offer new insights into ciliary assembly mechanisms and length control.
Related Concept Videos
01:39Mechanism of Filopodia Formation
2.4K
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
2.4K
01:31Mechanism of Lamellipodia Formation
2.6K
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
2.6K
01:23Catenins
2.3K
Catenins are characterized by multiple binding domains and dynamic structures that allow them to function as linker proteins in cell junction complexes. All catenins, except α-catenin, contain a characteristic protein sequence called the armadillo repeat and are therefore also called armadillo proteins.
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the...
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the...
2.3K
01:05Mechanism of Ciliary Motion
3.7K
The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
3.7K
02:19The Spindle Assembly Checkpoint
3.2K
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...
3.2K
01:32Assembly of Complex Microtubule Structures
1.9K
Complex microtubule structures are present in resting cells and in dividing cells. In resting cells, they are responsible for maintaining the cellular architecture, tracks for intracellular transport, positioning of organelles, assembly of cilia and flagella. They mediate the bipolar spindle assembly for chromosomal segregation and positioning of the cell division plate in dividing cells. The formation of microtubule complex structures depends on the cell type, cell stage, and cell function.
1.9K