Identification of candidate ciliary microtubule-associated proteins using CEP41 proximity labeling

CEP41 BioID proximity labeling and quantitative proteomics identified a ciliary MAP-enriched protein set, including novel ciliary MAPs C7orf57/FCAP33, CCDC34, and PSRC1, plus a poorly characterized Septin-9 isoform.

• Why it matters: Ciliary microtubule-associated proteins are clinically important in ciliopathies, but the specialized ciliary MAP repertoire remains incompletely defined.
• What they did: Using CEP41 as a BioID bait, the study performed quantitative proteomics with cilia-focused prioritization to find proteins proximal to ciliary microtubules, then tested CCDC34, PSRC1, and C7orf57 by functional assays and microtubule association analysis.
• The result: CCDC34 and PSRC1 did not affect cilia architecture or ciliation, while C7orf57 overexpression increased cilium length; C7orf57 is a paclitaxel-sensitive MAP associating with microtubules via its N-terminal regions.