Super-Resolution Architecture of Mammalian Centriole Distal Appendages Reveals Distinct Blade and Matrix Functional Components

Tony Yang^1,2*, Weng Man Chong³, Won-Jing Wang⁴, Gregory Mazo⁵, Barbara Tanos⁶, Zhengmin Chen³, Thi Minh Nguyet Tran³, Yi-De Chen³, Rueyhung Roc Weng³, Chia-En Huang³, Wann-Neng Jane⁷, Meng-Fu Bryan Tsou⁵, Jung-Chi Liao^3,8

¹Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
²Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
³Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
⁴Institute of Biochemistry and Molecular Biology, National Yang Ming University, Taipei, Taiwan
⁵Cell Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
⁶Institute of Cancer Research, London, UK
⁷Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
⁸Genome and Systems Biology Degree Program, National Taiwan University, Taipei, Taiwan

* Presenter:Tony Yang, email:tonyyang@ntu.edu.tw

Distal appendages (DAPs) are nanoscale, pinwheel-like structures protruding from the distal end of the centriole that mediate membrane docking during ciliogenesis, marking the cilia base around the ciliary gate. Here, we determine a superresolved multiplex of 16 centriole-distal-end components. Surprisingly, rather than pinwheels, intact DAPs exhibit a cone-shaped architecture with components filling the space between each pinwheel blade, a new structural element we term the distal appendage matrix (DAM). Specifically, CEP83, CEP89, SCLT1, and CEP164 form the backbone of pinwheel blades, with CEP83 confined at the root and CEP164 extending to the tip near the membrane-docking site. By contrast, FBF1 marks the distal end of the DAM near the ciliary membrane. Strikingly, unlike CEP164 which is essential for ciliogenesis, FBF1 is required for ciliary gating of transmembrane proteins, revealing DAPs as an essential component of the ciliary gate. Our findings redefine both the structure and function of DAPs.

Keywords: super-resolution, distal appendage, centriole