title: A NOMPC-dependent membrane-microtubule connector is a candidate for the gating spring in fly mechanoreceptors.
abstract: BACKGROUND
  Mechanoreceptors contain compliant elements, termed "gating springs," that transfer macroscopic stimuli impinging on the cells into microscopic stimuli that open the mechanosensitive channels. Evidence for gating springs comes from mechanical experiments; they have not been identified molecularly or ultrastructurally.
  
  
  RESULTS
  We show that the filamentous structures that connect the plasma membrane to the microtubules are compliant structural elements in the mechanoreceptive organelle of fly campaniform receptors. These filaments colocalize with the ankyrin-repeat domain of the transient receptor potential (TRP) channel NOMPC. In addition, they resemble the purified ankyrin-repeat domain in size and shape. Most importantly, these filaments are nearly absent in nompC mutants and can be rescued by the nompC gene. Finally, mechanical modeling suggests that the filaments provide most of the compliance in the distal tip of the cell, thought to be the site of mechanotransduction.
  
  
  CONCLUSIONS
  Our results provide strong evidence that the ankyrin-repeat domains of NOMPC structurally contribute to the membrane-microtubule connecting filaments. These filaments, as the most compliant element in the distal tip, are therefore good candidates for the gating springs.
authors.affiliation: Max-Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany.
authors.forename: Xin
authors.initials: X
authors.lastname: Liang
authors.forename: Johnson
authors.initials: J
authors.lastname: Madrid
authors.forename: Roland
authors.initials: R
authors.lastname: Gärtner
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Verbavatz
authors.forename: Christoph
authors.initials: C
authors.lastname: Schiklenk
authors.forename: Michaela
authors.initials: M
authors.lastname: Wilsch-Bräuninger
authors.forename: Aliona
authors.initials: A
authors.lastname: Bogdanova
authors.forename: Florian
authors.initials: F
authors.lastname: Stenger
authors.forename: Axel
authors.initials: A
authors.lastname: Voigt
authors.forename: Jonathon
authors.initials: J
authors.lastname: Howard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017089:Ankyrin Repeat; D003599:Cytoskeleton / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008465:Mechanoreceptors / Q000378:metabolism; D040542:Mechanotransduction, Cellular; D046529:Microscopy, Electron, Transmission; D016253:Microscopy, Immunoelectron; D008870:Microtubules / Q000378:metabolism; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D050051:Transient Receptor Potential Channels / Q000235:genetics* / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; C405783:NOMPC protein, Drosophila; D050051:Transient Receptor Potential Channels