Insights into the structure and function of ciliary and flagellar doublet microtubules: Tektins, Ca2+-binding proteins, and stable protofilaments

Richard Linck, Xiaofeng Fu, Jianfeng Lin, Christna Ouch, Alexandra Schefter, Walter Steffen, Peter Warren, Daniela Nicastro

Research output: Contribution to journalArticle

45 Scopus citations

Abstract

Cilia and flagella are conserved, motile, and sensory cell organelles involved in signal transduction and human disease. Their scaffold consists of a 9-fold array of remarkably stable doublet microtubules (DMTs), along which motor proteins transmit force for ciliary motility and intraflagellar transport. DMTs possess Ribbons of three to four hyper-stable protofilaments whose location, organization, and specialized functions have been elusive. We performed a comprehensive analysis of the distribution and structural arrangements of Ribbon proteins from sea urchin sperm flagella, using quantitative immunobiochemistry, proteomics, immuno-cryo-electron microscopy, and tomography. Isolated Ribbons contain acetylated α-tubulin, β-tubulin, conserved protein Rib45, >95% of the axonemal tektins, and >95% of the calcium-binding proteins, Rib74 and Rib85.5, whose human homologues are related to the cause of juvenile myoclonic epilepsy. DMT scontain only one type of Ribbon, corresponding to protofilaments A11-12-13-1 of the A-tubule. Rib74 and Rib85.5 are associated with the Ribbon in the lumen of the A-tubule. Ribbons contain a single ∼5-nm wide filament, composed of equimolar tektins A, B, and C, which interact with the nexin-dynein regulatory complex. A summary of findings is presented, and the functions of Ribbon proteins are discussed in terms of the assembly and stability of DMTs, ciliary motility, and other microtubule systems.

Original languageEnglish (US)
Pages (from-to)17427-17444
Number of pages18
JournalJournal of Biological Chemistry
Volume289
Issue number25
DOIs
StatePublished - Jun 20 2014

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Insights into the structure and function of ciliary and flagellar doublet microtubules: Tektins, Ca2+-binding proteins, and stable protofilaments'. Together they form a unique fingerprint.

  • Cite this