Photochemical cross-linking of both Tetrahymena and Aequipecten ciliary membrane proteins with the lipophilic reagent 4,4'-dithiobisphenylazide links together a high molecular weight dynein-like ATPase, membrane tubulin, and at least two other proteins. Electron microscopy of detergent-extracted cilia reveals that the cross-linked complex remains attached to the outer-doublet microtubules by a microtubule-membrane bridge. Cleavage of the reagent's disulfide bond releases the bridge-membrane complex and the dynein-like membrane-associated ATPase. Electron microscopy was used to ensure that the dynein-like protein did not result from the solubilization of the dynein arms attached to the outer-doublet microtubules. The dynein-like protein has been isolated using sucrose gradients and is similar to axonemal dynein with respect to its sedimentation characteristics nucleotide specificity, and divalent cation requirements. Photochemical cross-linking of ciliary membrane porteins in vivo results initially in the modification of ciliary beat and, eventually, in the cessation of ciliary movement. These results suggest that a dynein-like ATPase comprises the bridge which links the ciliary membrane to the outer-doublet microtubules and that this bridge is involved in the modulation of normal ciliary movement.
Microtubule-membrane interactions in cilia. II. Photochemical cross-linking of bridge structures and the identification of a membrane-associated dynein-like ATPase.
W L Dentler, M M Pratt, R E Stephens; Microtubule-membrane interactions in cilia. II. Photochemical cross-linking of bridge structures and the identification of a membrane-associated dynein-like ATPase.. J Cell Biol 1 February 1980; 84 (2): 381–403. doi: https://doi.org/10.1083/jcb.84.2.381
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