Document Type


Publication Date


Publication Title

The Journal of Cell Biology


Department of Biological Sciences


For virtually all cilia and eukaryotic flagella, the second messengers calcium and cyclic adenosine monophosphate are implicated in modulating dynein- driven microtubule sliding to regulate beating. Calmodulin (CaM) localizes to the axoneme and is a key calcium sensor involved in regulating motility. Using immunoprecipitation and mass spectrometry, we identify members of a CaM-containing complex that are involved in regulating dynein activity. This complex includes flagellar-associated protein 91 (FAP91), which shares considerable sequence similarity to AAT-1, a protein originally identified in testis as an A-kinase anchor protein (AKAP)- binding protein. FAP91 directly interacts with radial spoke protein 3 (an AKAP), which is located at the base of the spoke. In a microtubule sliding assay, the addition of antibodies generated against FAP91 to mutant axonemes with reduced dynein activity restores dynein activity to wild-type levels. These combined results indicate that the CaM- and spoke-associated complex mediates regulatory signals between the radial spokes and dynein arms.



Original Citation

Dymek EE, Smith EF. A conserved CaM- and radial spoke associated complex mediates regulation of flagellar dynein activity. J Cell Biol. 2007 Nov 5;179(3):515-26. doi: 10.1083/jcb.200703107. Epub 2007 Oct 29. PMID: 17967944; PMCID: PMC2064796.