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Updated: Jun 21, 2025
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Single Particle Cryo-Electron Microscopy: From Sample to Structure
Published on: May 29, 2021
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Architecture of RabL2-associated complexes at the ciliary base: A structural modeling perspective: Deciphering the
Niels Boegholm1, Narcis A Petriman1, Niaj M Tanvir1
1Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark.
Summary
Structural modeling reveals how RabL2 is anchored at the ciliary base via CEP19 before intraflagellar transport (IFT) trains facilitate its entry into cilia. This process involves CEP43, CEP350, and induces conformational changes in the IFT complex.
Area of Science:
- Cell Biology
- Structural Biology
- Molecular Motors
Background:
- Cilia are crucial eukaryotic organelles involved in signaling and locomotion.
- Intraflagellar transport (IFT) is essential for ciliary assembly and function.
- The precise mechanism of IFT complex assembly and ciliary entry at the basal body is not fully understood.
Purpose of the Study:
- To provide an architectural framework for RabL2 anchoring and handover to IFT trains at the ciliary base.
- To elucidate the structural interactions governing ciliary entry of IFT complexes.
- To understand how RabL2 association influences the IFT machinery.
Main Methods:
- Utilized structural modeling techniques.
- Investigated protein-protein interactions at the ciliary base.
- Analyzed the structural basis of RabL2-CEP19 and IFT-B complex association.
Main Results:
- Proposed a model where CEP43 homodimerizes with CEP350 to anchor at subdistal appendages.
- CEP43's C-terminal domain captures CEP19 near distal appendages.
- Modeled the RabL2-CEP19 association with the IFT-B complex, revealing conformational changes in IFT81/74 proteins.
Conclusions:
- The study provides a structural framework for RabL2's role in initiating ciliary entry.
- CEP43 acts as a scaffold, capturing CEP19 and facilitating RabL2 handover.
- RabL2 binding induces conformational changes in the IFT complex, potentially priming it for ciliary entry.
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