Comparative Super-Resolution Mapping of Basal Feet Reveals a Modular but Distinct Architecture in Primary and Motile Cilia

Abstract

Highlights d Basal foot proteins are organized into three main spatially distinct regions d The scaffolding and microtubule-anchoring regions are connected by NIN and CNTRL d NIN has a looping distribution and contributes to CNTRL primary cilia localization d BioID and super-resolution imaging identifies CEP112 as a basal foot protein

Super-Resolution Microscopy and FIB-SEM Imaging Reveal Parental Centriole-Derived, Hybrid Cilium in Mammalian Multiciliated Cells

“…We have recently resolved the molecular architecture of the basal foot in situ by super-resolution microscopy in primary and motile cilia (Nguyen et al, 2020). In the process of determining the molecular map of the basal foot in motile cilia, we discovered the presence of a ''hybrid'' cilium in multiciliated cells.…”

Sub-centrosomal mapping identifies augmin-γTuRC as part of a centriole-stabilizing scaffold

“…Centrosome targeting of γTuRC is regulated by accessory factors such as NEDD1 5,22 . Electron microscopy (EM) and, more recently, super-resolution microscopy have revealed localization of γTuRC subunits also at the subdistal appendages [23][24][25][26][27] and in the lumen of centrioles 6,[28][29][30][31][32][33][34] , but their roles at these sites were not investigated. During ciliogenesis, the mother centriole transforms into a basal body and templates formation of the axoneme, a microtubule-based structure that is at the core of cilia.…”

Basal Feet: Walking to the Discovery of a Novel Hybrid Cilium

“…Currently, they are classified as either motile or primary cilia, based on structural differences (Paintrand et al, 1992). In the pair of articles by Mennella and colleagues in the current issue of Developmental Cell (Liu et al, 2020;Nguyen et al, 2020), the authors use proteomics, super-resolution microscopy, and state-of-the-art electron microscopy techniques to investigate the organization of an important structural component of cilia, the basal foot, to resolve differences between primary and motile cilia. Over the course of this structural and functional analysis, the authors discover a ''hybrid'' cilium with characteristics of both motile and primary cilia with a unique and novel function.…”

“…A partial parts list of proteins that localize to the subdistal appendages (basal feet) are known from previous work (Kunimoto et al 2012;Gupta et al 2015). Using super-resolution and elec-tron microscopy of retinal pigmented epithelial cells that have a single primary cilium, Mennella and colleagues (Liu et al, 2020;Nguyen et al, 2020) investigated the architecture of basal feet. Analysis defined three regions linked by coiled-coil protein assemblies and determined protein positions relative to the basal body microtubules (Figure 1A).…”