CBY1

Cilia effects upon perturbation of CBY1

Cilia number / % ciliated:

Decreased cilia number

Loss-of-function effect:

Shorter cilia

Ciliogenesis screen results (4 screens)

• Wheway et al. 2015 (siRNA) [siRNA]: No effect PMID:26167766
• Breslow et al. 2018 (CRISPR) [CRISPR]: Positive Regulator (Hh signaling, casTLE effect=-3.27) PMID:29459680
• Pusapati et al. 2018 (CRISPR) [CRISPR]: Positive Regulator (Hh signaling, neg_rank=113, lfc=-3.27) PMID:30270045
• Elliott et al. 2025 (CRISPRa) [CRISPRa]: Disassembly Trigger (casTLE Effect=-3.65) PMID:41160700

Phenotypes

Human ciliopathy phenotype:

Joubert syndrome

Ciliopathy associations

• Joubert Syndrome

Subcellular localization

basal body, nucleus, transition zone

Functional category

• Ciliary assembly/disassembly
• T cell biology
• Ciliary membrane
• Cardiac & muscle development
• Transition zone

Function

Inhibits beta-catenin-mediated transcriptio l activation by competing with Tcf/Lef. Cby1 is required for recruitment of Arl13b to the primary cilium. Promotes Ahi1 localisation to the centriole and is probably important for assembly and function of transition zone components (25103236). Cby1 may associate with membranes to promote the recruitment of FAM92 proteins for their higher-order assembly and subsequent membrane remodelling to promote ciliogenesis (27528616). Because of its proximity to the membrane vesicle, it is possible that Cby proteins may be involved in targeting and/or attachmentof the vesicles to the centriole, controlling intraflagellar transport and protein sorting of the ciliary membrane (22911743). "Cby1 localizes to the base of primary cilia (Fig. 5), and both number and length of primary cilia are significantly reduced in the pancreas of Cby1-KO mice. There was a 41% decrease in the number of primary cilia in Cby1-KO islets compared to WT islets (https://doi.org/10.1038/s41598-021-96597-w).

Model organism evidence