Proximity Mapping of Ciliary Proteins by BioID.

Abstract

The primary cilium is a highly conserved microtubule-based organelle present in most vertebrate cell types. Mutations in ciliary protein genes can lead to dysfunctional or absent cilia and are the cause of a large group of heterogeneous diseases known as ciliopathies. ARL13Bis a member of the ARF family of regulatory GTPases and is highly enriched on the ciliary membrane. The absence ofARL13B disrupts cilia architecture and mutations have been linked to several diseases; yet there remain major gaps in our understanding of the role thatARL13B plays in primary cilia function. Here, we demonstrate how in cellulo proximity-dependent biotinylation (BioID) can be used to generate a comprehensive protein proximity map of ciliary proteins by performing BioID on N- and C-terminally BirA*-taggedARL13B. This method can theoretically provide insight into any cilia protein, identifying key interactors that play a critical role in ciliary biology.