Related Experiment Video
Updated: May 13, 2026
08:14
Using Primary Neurosphere Cultures to Study Primary Cilia
Published on: April 14, 2017
Vertebrate Smoothened functions at the primary cilium
Kevin C Corbit1, Pia Aanstad, Veena Singla
1Developmental and Stem Cell Biology Program, University of California, San Francisco, California 94143, USA.
Nature
|September 2, 2005
Summary
Mammalian Hedgehog (Hh) pathway signaling relies on Smoothened (Smo) protein localization to primary cilia. This ciliary translocation is crucial for Smo function and Hh pathway activity.
Area of Science:
- Cell Biology
- Developmental Biology
- Molecular Biology
Background:
- Intraflagellar transport proteins link cilia and the Hedgehog (Hh) pathway.
- The role of cilia in Hh signal transduction is increasingly recognized.
Purpose of the Study:
- To investigate the ciliary localization and function of mammalian Smoothened (Smo).
- To determine the regulatory mechanisms controlling Smo's presence in primary cilia.
Main Methods:
- Immunofluorescence microscopy to detect Smo localization in primary cilia.
- Functional assays in cultured cells and zebrafish embryos to assess Smo activity.
- Site-directed mutagenesis to identify critical domains for ciliary localization.
Main Results:
- Mammalian Smo is localized to primary cilia in a Hh pathway-dependent manner.
- Hedgehog pathway activation or Smo mutations promote ciliary localization; antagonists inhibit it.
- A conserved domain is essential for Smo's ciliary translocation and downstream signaling.
Conclusions:
- Hedgehog-dependent translocation to primary cilia is essential for Smo protein activity.
- The primary cilium serves as a critical site for Smo function in Hh signaling.
Related Concept Videos
01:24Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
01:22Microtubules in Signaling
The primary cilium, made up of microtubules, acts as antennae on the cell surfaces for relaying external stimuli into the cells. These fine hair-like structures are present, generally one per cell. These are non-motile cilia in a 9+0 microtubules arrangement, where the central pair of microtubules are absent. The primary cilia arise from the basal body embedded in the cell membrane. Intraflagellar transport (IFT) carries requisite proteins from the cytoplasm to the cilium because the primary...
01:16Cell Motility through Blebbing
Blebs are a type of membrane protrusion formed by the internal hydrostatic pressure of the cytoplasm. Blebs are observed in several cell types, including fibroblasts, immune cells, and single-celled organisms like the amoeba. The primary function of blebs is cell locomotion and apoptosis, but they are also found during necrosis and cell division. The life cycle of a bleb comprises an initiation phase followed by the expansion and retraction phases.
Blebbing Through the Matrix
In multicellular...
Blebbing Through the Matrix
In multicellular...
01:05Mechanism of Ciliary Motion
The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
01:24Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...
01:05Mechanism of Ciliary Motion
The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...