Characterization of an apical ceramide-enriched compartment regulating ciliogenesis

Qian He, Guanghu Wang, Somsankar Dasgupta, Michael Dinkins, Gu Zhu, Erhard Bieberich

Research output: Contribution to journalArticlepeer-review

34 Scopus citations

Abstract

We show that in Madin-Darby canine kidney (MDCK) cells, an apical ceramide- enriched compartment (ACEC) at the base of primary cilia is colocalized with Rab11a. Ceramide and Rab11a vesicles isolated by magnetic sorting contain a highly similar profile of proteins (atypical protein kinase C [aPKC], Cdc42, Sec8, Rab11a, and Rab8) and ceramide species, suggesting the presence of a ciliogenic protein complex associated with ceramide at the ACEC. It is intriguing that C16 and C18 ceramide, although less abundant ceramide species in MDCK cells, are highly enriched in ceramide and Rab11a vesicles. Expression of a ceramide-binding but dominant-negative mutant of aPKC suppresses ciliogenesis, indicating that the association of ceramide with aPKC is critical for the formation of this complex. Our results indicate that ciliogenic ceramide is derived from apical sphingomyelin (SM) that is endocytosed and then converted to the ACEC. Consistently, inhibition of acid sphingomyelinase with imipramine disrupts ACEC formation, association of ciliogenic proteins with Rab11a vesicles, and cilium formation. Ciliogenesis is rescued by the histone deacetylase (HDAC) inhibitor trichostatin A, indicating that ceramide promotes tubulin acetylation in cilia. Taken together, our results suggest that the ACEC is a novel compartment in which SM-derived ceramide induces formation of a ciliogenic lipid-protein complex that sustains primary cilia by preventing deacetylation of microtubules.

Original languageEnglish (US)
Pages (from-to)3156-3166
Number of pages11
JournalMolecular Biology of the Cell
Volume23
Issue number16
DOIs
StatePublished - Aug 15 2012

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

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