Direct evidence for BBSome-associated intraflagellar transport reveals distinct properties of native mammalian cilia

Nat Commun. 2014 Dec 15;5:5813. doi: 10.1038/ncomms6813.

Abstract

Cilia dysfunction underlies a class of human diseases with variable penetrance in different organ systems. Across eukaryotes, intraflagellar transport (IFT) facilitates cilia biogenesis and cargo trafficking, but our understanding of mammalian IFT is insufficient. Here we perform live analysis of cilia ultrastructure, composition and cargo transport in native mammalian tissue using olfactory sensory neurons. Proximal and distal axonemes of these neurons show no bias towards IFT kinesin-2 choice, and Kif17 homodimer is dispensable for distal segment IFT. We identify Bardet-Biedl syndrome proteins (BBSome) as bona fide constituents of IFT in olfactory sensory neurons, and show that they exist in 1:1 stoichiometry with IFT particles. Conversely, subpopulations of peripheral membrane proteins, as well as transmembrane olfactory signalling pathway components, are capable of IFT but with significantly less frequency and/or duration. Our results yield a model for IFT and cargo trafficking in native mammalian cilia and may explain the penetrance of specific ciliopathy phenotypes in olfactory neurons.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adenoviridae / genetics
  • Animals
  • Axoneme / metabolism*
  • Axoneme / ultrastructure
  • Biological Transport
  • Cilia / metabolism*
  • Cilia / ultrastructure
  • Flagella / metabolism*
  • Flagella / ultrastructure
  • Gene Expression Regulation*
  • Genes, Reporter
  • Genetic Vectors
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Kinesin / genetics
  • Kinesin / metabolism
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Mice
  • Mice, Transgenic
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism
  • Olfactory Receptor Neurons / metabolism*
  • Olfactory Receptor Neurons / ultrastructure
  • Proteins / genetics
  • Proteins / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction*

Substances

  • BBS4 protein, mouse
  • Bbs1 protein, mouse
  • Bbs2 protein, mouse
  • KIF17 protein, mouse
  • Luminescent Proteins
  • Microtubule-Associated Proteins
  • Proteins
  • Recombinant Fusion Proteins
  • kinesin light-chain proteins
  • red fluorescent protein
  • Green Fluorescent Proteins
  • Kinesin