Related Experiment Video
Updated: May 31, 2026
06:08
Biophysical Characterization of Flagellar Motor Functions
Published on: January 18, 2017
Sequential assembly of flagellar radial spokes.
Dennis R Diener1, Pinfen Yang, Stefan Geimer
1Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA.
Cytoskeleton (Hoboken, N.J.)
|June 22, 2011
Summary
Chlamydomonas radial spoke assembly occurs in the cell body. Researchers used mutant analysis to demonstrate in vitro assembly of radial spoke proteins (RSPs), revealing stepwise assembly pathways.
Area of Science:
- Cell biology
- Molecular biology
- Biochemistry
Background:
- The unicellular alga Chlamydomonas assembles complex flagella.
- Flagellar radial spokes are crucial structures for motility.
- Preassembly of macromolecular complexes in the cell body simplifies protein targeting.
Purpose of the Study:
- To investigate the stepwise assembly of radial spokes in Chlamydomonas.
- To elucidate the order of radial spoke protein (RSP) assembly.
- To demonstrate in vitro assembly of radial spoke subcomplexes.
Main Methods:
- Analysis of Chlamydomonas mutants lacking specific radial spoke proteins (RSPs).
- Biochemical analysis of protein complexes from cell extracts.
- In vitro mixing of mutant extracts to observe complex formation.
Main Results:
- Radial spokes are partially assembled into a 12S complex in the cell body.
- Mutants lacking single RSPs revealed smaller spoke subassemblies.
- Mixing mutant extracts in vitro allowed the assembly of the 12S complex from smaller components.
Conclusions:
- The stepwise assembly of radial spokes can be recapitulated in vitro.
- This study provides insights into the ordered assembly pathway of flagellar radial spokes.
- Understanding radial spoke assembly is key to flagellar function and motility.
Related Concept Videos
02:50Spindle Assembly
Spindle assembly occurs through three, often coexisting, pathways – the centrosome-mediated pathway, the chromatin-mediated pathway, and the microtubule-mediated pathway – collectively contributing to form a robust spindle apparatus.
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
02:50Spindle Assembly
Spindle assembly occurs through three, often coexisting, pathways – the centrosome-mediated pathway, the chromatin-mediated pathway, and the microtubule-mediated pathway – collectively contributing to form a robust spindle apparatus.
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
01:39Mechanism of Filopodia Formation
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...
01:31Mechanism of Lamellipodia Formation
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...
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...