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Updated: Apr 17, 2026

2D and 3D Human Induced Pluripotent Stem Cell-Based Models to Dissect Primary Cilium Involvement during Neocortical Development
Published on: March 25, 2022
Early steps in primary cilium assembly require EHD1/EHD3-dependent ciliary vesicle formation
Quanlong Lu1, Christine Insinna1, Carolyn Ott2
1NCI-Frederick National Laboratory, Laboratory of Cellular and Developmental Signaling, Frederick, MD 21702, USA.
Membrane proteins EHD1 and EHD3 reorganize the mother centriole (M-centriole) and vesicles, initiating ciliary membrane assembly. This process is crucial for ciliogenesis before axoneme growth.
Area of Science:
- Cell Biology
- Molecular Biology
- Cilia Biology
Background:
- Cilia formation (ciliogenesis) requires precise membrane assembly, initiated by mother centriole (M-centriole) distal appendages.
- The role of the Rab GTPase Rab11-Rab8 cascade in early ciliary membrane assembly remains unclear.
Purpose of the Study:
- To elucidate the function of EHD1 and EHD3 proteins in the early stages of ciliogenesis.
- To investigate the interplay between EHD proteins, the Rab11-Rab8 cascade, and ciliary membrane assembly.
Main Methods:
- Immunofluorescence microscopy to determine protein localization (EHD1, EHD3, IFT20).
- Analysis of ciliary vesicle formation and M-centriole to basal body transformation.
- Investigating the role of SNAP29 in vesicle assembly.
Main Results:
- EHD1 and EHD3 localize to preciliary membranes and the ciliary pocket, driving membrane tubulation for ciliary vesicle formation from distal appendage vesicles (DAVs).
- This EHD-dependent step is essential for M-centriole to basal body transformation and the recruitment of transition zone proteins and IFT20.
- SNAP29 is required for DAV-mediated ciliary vesicle assembly, and Rab8 activation for ciliary growth occurs only after vesicle assembly.
Conclusions:
- EHD1 and EHD3, with the Rab11-Rab8 cascade, orchestrate a novel ciliogenesis step involving M-centriole and DAV reorganization.
- This precedes coordinated ciliary membrane and axoneme growth, revealing key molecular mechanisms in early ciliogenesis.
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