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A septin diffusion barrier at the base of the primary cilium maintains ciliary membrane protein distribution.

ABSTRACT: In animal cells, the primary cilium transduces extracellular signals through signaling receptors localized in the ciliary membrane, but how these ciliary membrane proteins are retained in the cilium is unknown. We found that ciliary membrane proteins were highly mobile, but their diffusion was impeded at the base of the cilium by a diffusion barrier. Septin 2 (SEPT2), a member of the septin family of guanosine triphosphatases that form a diffusion barrier in budding yeast, localized at the base of the ciliary membrane. SEPT2 depletion resulted in loss of ciliary membrane protein localization and Sonic hedgehog signal transduction, and inhibited ciliogenesis. Thus, SEPT2 is part of a diffusion barrier at the base of the ciliary membrane and is essential for retaining receptor-signaling pathways in the primary cilium.

SUBMITTER: Hu Q

PROVIDER: S-EPMC3092790 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature

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A septin diffusion barrier at the base of the primary cilium maintains ciliary membrane protein distribution.

Hu Qicong Q Milenkovic Ljiljana L Jin Hua H Scott Matthew P MP Nachury Maxence V MV Spiliotis Elias T ET Nelson W James WJ

Science (New York, N.Y.) 20100617 5990

In animal cells, the primary cilium transduces extracellular signals through signaling receptors localized in the ciliary membrane, but how these ciliary membrane proteins are retained in the cilium is unknown. We found that ciliary membrane proteins were highly mobile, but their diffusion was impeded at the base of the cilium by a diffusion barrier. Septin 2 (SEPT2), a member of the septin family of guanosine triphosphatases that form a diffusion barrier in budding yeast, localized at the base ...[more]

PMID: 20558667

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