The RNA splicing factor PRPF8 is required for left-right organiser cilia function and determination of cardiac left-right asymmetry via regulation of Arl13b splicing

Jiang, F.; Boylan, M.; Maxwell, D. W.; Qureshi, W. M. S.; Rowlands, C. F.; Tenin, G.; Mitchell, K.; Stephen, L. A.; Vasconcelos, E. J.; Wang, D.; Chen, T.; Zha, J.; Liu, J.; Althali, N.; Leordean, D. V.; Gallagher, M. T.; Basu, B.; Szymanska, K.; Veeraghanta, A.; Keavney, B.; Humphries, M. J.; Ellingford, J. M.; Smith, D.; Johnson, C. A.; O'Keefe, R. A.; Roy, S.; Hentges, K. E.

doi:10.1101/2025.05.22.654869

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bioRxiv · 10.1101/2025.05.22.654869

The RNA splicing factor PRPF8 is required for left-right organiser cilia function and determination of cardiac left-right asymmetry via regulation of Arl13b splicing

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Abstract

Cilia function in the left-right organizer (LRO) is critical for determining internal organ asymmetry in vertebrates. To further understand the genetics of left-right asymmetry, we isolated a mouse mutant with laterality defects, l11Jus27, from a random mutagenesis screen. l11Jus27 mutants carry a missense mutation in the pre-mRNA processing factor, Prpf8. cephaloph[o]nus (cph) mutant zebrafish, carrying a protein truncating mutation in prpf8, phenocopy the laterality defects of l11Jus27 mutants. Prpf8 mutant mouse and fish embryos have increased expression of an alternative transcript encoding the cilium-associated protein, ARL13B, that lacks exon 9. In zebrafish, over-expression of the arl13b transcript lacking exon 9 perturbed cilium formation and caused laterality defects. The shorter ARL13B protein isoform lacked interactions with intraflagellar transport proteins. Our data suggest that PRPF8 plays a prominent role in LRO cilia by through the regulation of alternative splicing of ARL13B, thus uncovering a new mechanism for cilia-linked developmental defects.

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Jiang, F., Boylan, M., Maxwell, D. W., Qureshi, W. M. S., Rowlands, C. F., Tenin, G., Mitchell, K., Stephen, L. A., Vasconcelos, E. J., Wang, D., Chen, T., Zha, J., Liu, J., Althali, N., Leordean, D. V., Gallagher, M. T., Basu, B., Szymanska, K., Veeraghanta, A., Keavney, B., Humphries, M. J., Ellingford, J. M., Smith, D., Johnson, C. A., O'Keefe, R. A., Roy, S., Hentges, K. E.. 2025-05-27. The RNA splicing factor PRPF8 is required for left-right organiser cilia function and determination of cardiac left-right asymmetry via regulation of Arl13b splicing. https://doi.org/10.1101/2025.05.22.654869

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