Flagellar Kinesins in Protists

Abstract

Cilia and flagella are organelles of the cell body present in many eukaryotic cells. Although their basic structure is well conserved from unicellular organisms to mammals, they show amazing diversity in number, structure, molecular composition, disposition and function. These complex organelles are generally assembled by the action of intraflagellar transport, which is powered by kinesin and dynein motor proteins. Several types of kinesins can function in flagella. They all have a well-conserved motor domain with characteristic signatures, but display exhaustive diversification of some domains. This diversity can be explained by the multitude of functions fulfilled by these proteins (transport of cargoes along microtubules, polymerization and depolymerization of microtubules). Functional and phylogenetic analyses reveal that at least seven kinesin families are involved in flagellum assembly and function. In protists, where cilia and flagella fulfill many essential roles, this diversity of function is also observed.

Keywords:

• diversity
• evolution
• flagellum
• IFT
• kinesin
• microtubule
• protists

Acknowledgements

The authors are grateful to P Bastin for his invaluable comments on the manuscript and anonymous referees for constructive suggestions. They also thank R Demonchy for his enthusiastic discussions at the start of this work. The authors wish to thank T Blisnick and P Bastin for their wonderful scanning image and L Pedersen for granting permission to use the intraflagellar transport figure.

Financial & competing interests disclosure

W Marande is funded by an ANR contract ‘SENSOTRYPA‘ (ANR-08-MIE-027) by the French Ministry of Research. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Additional information

Funding

W Marande is funded by an ANR contract ‘SENSOTRYPA‘ (ANR-08-MIE-027) by the French Ministry of Research. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.