Related Experiment Video
Updated: Jul 16, 2026
07:20
Simultaneous Visualization of the Dynamics of Crosslinked and Single Microtubules In Vitro by TIRF Microscopy
Published on: February 18, 2022
Structural insights into microtubule doublet interactions in axonemes
Kenneth H Downing1, Haixin Sui
1Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. khdowning@lbl.gov
Current Opinion in Structural Biology
|March 28, 2007
Summary
Dynein motors drive microtubule doublet sliding for ciliary and flagellar beating. Cryo-electron tomography reveals protein interactions and structural basis for movement regulation in the axoneme.
Area of Science:
- Cell biology
- Biophysics
- Structural biology
Background:
- Eukaryotic cilia and flagella beat through coordinated sliding of microtubule doublets powered by dynein motors.
- The axoneme, the core structure of cilia and flagella, comprises numerous proteins that regulate movement.
Purpose of the Study:
- To elucidate the structural basis of coordinated movement in cilia and flagella.
- To understand the role of protein interactions, particularly dyneins, in regulating axonemal function.
Main Methods:
- Cryo-electron tomography was employed to visualize the axoneme at high resolution.
- Structural studies of isolated microtubule doublets were conducted.
Main Results:
- New details of protein interactions within the axoneme were revealed.
- Specific connections between different dynein types suggest coordination mechanisms.
- The molecular architecture of doublets provides insights into mechanical properties and dynein regulation.
Conclusions:
- Structural insights from cryo-electron tomography enhance understanding of ciliary and flagellar motility.
- The study provides a structural framework for investigating dynein motor regulation and axonemal mechanics.
Related Concept Videos
01:24Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
01:24Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
01:32Assembly of Complex Microtubule Structures
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.
01:18Microtubules
Microtubules are the thickest cytoskeletal filaments with a diameter of 25 nm. In prokaryotic organisms, microtubules are commonly found in locomotory appendages like cilia and flagella. In eukaryotic cells, microtubules form specialized extensions for moving fluid over the surface, like those found in cells lining the intestine.
Microtubules have two structurally similar globular protein subunits: α and β tubulins. In the cytosol, the α and β tubulins form a heterodimer. These αβ-heterodimers...
Microtubules have two structurally similar globular protein subunits: α and β tubulins. In the cytosol, the α and β tubulins form a heterodimer. These αβ-heterodimers...
01:35Microtubules
There are three types of cytoskeletal structures in eukaryotic cells—microfilaments, intermediate filaments, and microtubules. With a diameter of about 25 nm, microtubules are the thickest of these fibers. Microtubules carry out a variety of functions that include cell structure and support, transport of organelles, cell motility (movement), and the separation of chromosomes during cell division.Microtubules are hollow tubes whose walls are made up of globular tubulin proteins. Each tubulin...
01:39Anaphase A and B
Microtubules form through the end-to-end polymerization of tubulin heterodimers. Kinetochore microtubules originate from the spindle poles, and their plus-ends connect with the kinetochores on sister-chromatids. Ndc80 protein complexes, present on the kinetochore, form low-affinity links with the plus end of these kinetochore microtubules.
Plus-end depolymerization releases tubulin heterodimers from the terminal region of the microtubule. As tubulin subunits are lost, the Ndc80 complexes detach...
Plus-end depolymerization releases tubulin heterodimers from the terminal region of the microtubule. As tubulin subunits are lost, the Ndc80 complexes detach...