A role for the inositol kinase Ipk1 in ciliary beating and length maintenance

Proc Natl Acad Sci U S A. 2007 Dec 11;104(50):19843-8. doi: 10.1073/pnas.0706934104. Epub 2007 Dec 3.

Abstract

Cilia project from cells as membranous extensions, with microtubule structural cores assembling from basal bodies by intraflagellar transport (IFT). Here, we report a ciliary role for the inositol 1,3,4,5,6-pentakisphosphate 2-kinase (Ipk1) that generates inositol hexakisphosphate. In zebrafish embryos, reducing Ipk1 levels inhibited ciliary beating in Kupffer's vesicle and decreased ciliary length in the spinal canal, pronephric ducts, and Kupffer's vesicle. Electron microscopy showed that ciliary axonemal structures were not grossly altered. However, coincident knockdown of Ipk1 and IFT88 or IFT57 had synergistic perturbations. With GFP-Ipk1 enriched in centrosomes and basal bodies, we propose that Ipk1 plays a previously uncharacterized role in ciliary function.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Biological Transport
  • Body Patterning
  • Cell Line
  • Centrosome / metabolism
  • Cilia / enzymology*
  • Cilia / physiology*
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Enzymologic
  • Humans
  • Microtubules / metabolism
  • Phosphotransferases (Alcohol Group Acceptor) / genetics
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / metabolism*
  • Zebrafish* / embryology
  • Zebrafish* / genetics
  • Zebrafish* / metabolism

Substances

  • Protozoan Proteins
  • Zebrafish Proteins
  • Phosphotransferases (Alcohol Group Acceptor)
  • ippk protein, zebrafish