Centriole distal appendages promote membrane docking, leading to cilia initiation

Barbara E. Tanos; Hui-Ju Yang; Rajesh Soni; Won-Jing Wang; Frank P. Macaluso; John M. Asara; Meng-Fu Bryan Tsou

doi:10.1101/gad.207043.112

Centriole distal appendages promote membrane docking, leading to cilia initiation

¹Cell Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA;
²Analytical Imaging Facility, Albert Einstein College of Medicine, Bronx, New York 10461, USA;
³Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, USA;
⁴Mass Spectrometry Core, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, USA;
⁵Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York 10065, USA

↵6 Present address: Department of Frontier Biosciences, Osaka University, Osaka, Japan.

Abstract

The distal appendages (DAPs) of centrioles have been proposed to anchor cilia to the plasma membrane, but their molecular composition, assembly, and exact function in ciliogenesis remain poorly understood. Using quantitative centrosome proteomics and superresolution microscopy, we identified five DAP components, including one previously described (CEP164), one partially characterized (CEP89 [ccdc123]), and three novel (CEP83 [ccdc41], SCLT1, and FBF1) DAP proteins. Analyses of DAP assembly revealed a hierarchy. CEP83 recruits both SCLT1 and CEP89 to centrioles. Subsequent recruitment of FBF1 and CEP164 is independent of CEP89 but mediated by SCLT1. All five DAP components are essential for ciliogenesis; loss of CEP83 specifically blocks centriole-to-membrane docking. Undocked centrioles fail to recruit TTBK2 or release CP110, the two earliest modifications found on centrioles prior to cilia assembly, revealing centriole-to-membrane docking as a temporal and spatial cue promoting cilia initiation.