Document Type
Article
Language
eng
Publication Date
1-2008
Publisher
Rockefeller University Press
Source Publication
Journal of Cell Biology
Source ISSN
0021-9525
Original Item ID
DOI: 10.1083/jcb.200705069
Abstract
T-shape radial spokes regulate flagellar beating. However, the precise function and molecular mechanism of these spokes remain unclear. Interestingly, Chlamydomonas reinhardtii flagella lacking a dimeric heat shock protein (HSP) 40 at the spokehead–spokestalk juncture appear normal in length and composition but twitch actively while cells jiggle without procession, resembling a central pair (CP) mutant. HSP40− cells begin swimming upon electroporation with recombinant HSP40. Surprisingly, the rescue doesn't require the signature DnaJ domain. Furthermore, the His-Pro-Asp tripeptide that is essential for stimulating HSP70 adenosine triphosphatase diverges in candidate orthologues, including human DnaJB13. Video microscopy reveals hesitance in bend initiation and propagation as well as irregular stalling and stroke switching despite fairly normal waveform. The in vivo evidence suggests that the evolutionarily conserved HSP40 specifically transforms multiple spoke proteins into stable conformation capable of mechanically coupling the CP with dynein motors. This enables 9 + 2 cilia and flagella to bend and switch to generate alternate power strokes and recovery strokes.
Recommended Citation
Yang, Chun; Owen, Heather A.; and Yang, Pinfen, "Dimeric Heat Shock Protein 40 Binds Radial Spokes for Generating Coupled Power Strokes and Recovery Strokes of 9 + 2 Flagella" (2008). Biological Sciences Faculty Research and Publications. 368.
https://epublications.marquette.edu/bio_fac/368
Comments
Published version. Journal of Cell Biology, Vol. 180, No. 2 (January 2008): 403-415. DOI. © 2008 Rockefeller University Press. Used with permission.