Axonemal dyneins

The cytosolic dyneins bear many similarities to axonemal dynein. The protein isolated from C. elegans includes a heavy chain with a molecular mass of approximately 400 kD, as well as smaller peptides with molecular mass ranging from 53 kD to 74 kD. The protein possesses a microtubule-activated ATPase... 

Even though dynein, kinesin, and myosin serve similar ATPase-dependent chemomechanical functions and have structural similarities, they do not appear to be related to each other in molecular terms. Their similarity lies in the overall shape of the molecule, which is composed of a pair of globular heads that bind microtubules and a fan-shaped tail piece (not present in myosin) that is suspected to carry the attachment site for membranous vesicles and other cytoplasmic components transported by MT. The cytoplasmic and axonemal dyneins are similar in structure (Hirokawa et al., 1989 Holzbaur and Vallee, 1994). Current studies on mutant phenotypes are likely to lead to a better understanding of the cellular roles of molecular motor proteins and their mechanisms of action (Endow and Titus, 1992). 

Fang Y-I, Yokota E, Mabuchi I, Nakamura H, Ohizumi Y (1997) Purealin Blocks the Sliding Movement of Sea Urchin Flagellar Axonemes by Selective Inhibition of Half the ATPase Activity of Axonemal Dyneins. Biochemistry 36 15561... 

Eukaryotic Cilia and Flagella Contain a Core of Doublet Microtubules Studded with Axonemal Dyneins... 

See also Motions of Cilia and Flagella, Axoneme, Dynein... 

Kikushima, K., Yagi, T., and Kamiya, R. (2004) Slow ADP-dependent acceleration of microtubule translocation produced by an axonemal dynein, FEBS Lett. 563, 119-122. 

In addition to axonemal dyneins, there are cytoplasmic dyneins, distinct isoforms that transport molecular cargoes along cytoplasmic microtubules and participate in aspects of cell division (Karki and Holzbaur 1999). 

The Dynein superfamily of proteins was introduced in 1965 [59]. Dyneins exist in two isoforms, the cytoplasmic and the axonemal. Cytoplasmic dyneins are involved in cargo movement, while axonemal dyneins are involved in producing bending motions of cilia and flagella [60-70]. Figure 19.9 shows a typical cytoplasmic dynein molecule. 

Ibanez-Tallon, 1., Pagenstecher, A., Fliegauf, M., Olbrich, H., Kispert, A., Ketelsen, U.-P., North, A., Heintz, N., and Omran, H. (2004) Dysfunction of axonemal dynein heavy chain Mdnah5 inhibits ependymal flow and reveals a novel mechanism for hydrocephalus formation. Hum. Mol Genet., 13, 2133-2141. 

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