Limits...
Localization of calmodulin and dynein light chain LC8 in flagellar radial spokes.

Yang P, Diener DR, Rosenbaum JL, Sale WS - J. Cell Biol. (2001)

Bottom Line: The isolated radial spokes sediment as 20S complexes that are the size and shape of radial spokes.Extracted radial spokes rescue radial spoke structure when reconstituted with isolated axonemes derived from the radial spoke mutant pf14.Isolated radial spokes are composed of the 17 previously defined spoke proteins as well as at least five additional proteins including calmodulin and the ubiquitous dynein light chain LC8.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Emory University, School of Medicine, Atlanta, Georgia 30322, USA.

ABSTRACT
Genetic and in vitro analyses have revealed that radial spokes play a crucial role in regulation of ciliary and flagellar motility, including control of waveform. However, the mechanisms of regulation are not understood. Here, we developed a novel procedure to isolate intact radial spokes as a step toward understanding the mechanism by which these complexes regulate dynein activity. The isolated radial spokes sediment as 20S complexes that are the size and shape of radial spokes. Extracted radial spokes rescue radial spoke structure when reconstituted with isolated axonemes derived from the radial spoke mutant pf14. Isolated radial spokes are composed of the 17 previously defined spoke proteins as well as at least five additional proteins including calmodulin and the ubiquitous dynein light chain LC8. Analyses of flagellar mutants and chemical cross-linking studies demonstrated calmodulin and LC8 form a complex located in the radial spoke stalk. We postulate that calmodulin, located in the radial spoke stalk, plays a role in calcium control of flagellar bending.

Show MeSH

Related in: MedlinePlus

Two models depicting the possible location of the key proteins in the radial spoke stalk including, LC8, calmodulin, RSP2, and RSP3.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2192029&req=5

Figure 9: Two models depicting the possible location of the key proteins in the radial spoke stalk including, LC8, calmodulin, RSP2, and RSP3.

Mentions: Based on our results, LC8, calmodulin, and RSP2 are part of the radial spoke stalk (Fig. 9). Currently, we favor model 1 (Fig. 9), localizing the LC8–calmodulin–RSP2 complex of at the proximal end of the spoke stalk. This hypothesis is based on localization of RSP3 at the proximal end of the spoke stalk (Diener et al. 1993), prediction that LC8 binds to RSP3 (see above; Lo et al. 2001), interaction between LC8 and calmodulin in the spoke stalk (Fig. 8), and RSP2 binding to calmodulin (Yang, P., and W.S. Sale, manuscript in preparation). However, distinguishing between model 1 and model 2 will require new structural and biochemical approaches.


Localization of calmodulin and dynein light chain LC8 in flagellar radial spokes.

Yang P, Diener DR, Rosenbaum JL, Sale WS - J. Cell Biol. (2001)

Two models depicting the possible location of the key proteins in the radial spoke stalk including, LC8, calmodulin, RSP2, and RSP3.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2192029&req=5

Figure 9: Two models depicting the possible location of the key proteins in the radial spoke stalk including, LC8, calmodulin, RSP2, and RSP3.
Mentions: Based on our results, LC8, calmodulin, and RSP2 are part of the radial spoke stalk (Fig. 9). Currently, we favor model 1 (Fig. 9), localizing the LC8–calmodulin–RSP2 complex of at the proximal end of the spoke stalk. This hypothesis is based on localization of RSP3 at the proximal end of the spoke stalk (Diener et al. 1993), prediction that LC8 binds to RSP3 (see above; Lo et al. 2001), interaction between LC8 and calmodulin in the spoke stalk (Fig. 8), and RSP2 binding to calmodulin (Yang, P., and W.S. Sale, manuscript in preparation). However, distinguishing between model 1 and model 2 will require new structural and biochemical approaches.

Bottom Line: The isolated radial spokes sediment as 20S complexes that are the size and shape of radial spokes.Extracted radial spokes rescue radial spoke structure when reconstituted with isolated axonemes derived from the radial spoke mutant pf14.Isolated radial spokes are composed of the 17 previously defined spoke proteins as well as at least five additional proteins including calmodulin and the ubiquitous dynein light chain LC8.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Emory University, School of Medicine, Atlanta, Georgia 30322, USA.

ABSTRACT
Genetic and in vitro analyses have revealed that radial spokes play a crucial role in regulation of ciliary and flagellar motility, including control of waveform. However, the mechanisms of regulation are not understood. Here, we developed a novel procedure to isolate intact radial spokes as a step toward understanding the mechanism by which these complexes regulate dynein activity. The isolated radial spokes sediment as 20S complexes that are the size and shape of radial spokes. Extracted radial spokes rescue radial spoke structure when reconstituted with isolated axonemes derived from the radial spoke mutant pf14. Isolated radial spokes are composed of the 17 previously defined spoke proteins as well as at least five additional proteins including calmodulin and the ubiquitous dynein light chain LC8. Analyses of flagellar mutants and chemical cross-linking studies demonstrated calmodulin and LC8 form a complex located in the radial spoke stalk. We postulate that calmodulin, located in the radial spoke stalk, plays a role in calcium control of flagellar bending.

Show MeSH
Related in: MedlinePlus