A dual role for the RNA helicase DHX34 in NMDand pre-mRNA splicing and its function inhematopoietic differentiation

Hug, N.; Aitken, S.; Longman, D.; Raab, M.; Armes, H.; Mann, A. R.; Rio-Machin, A.; Fitzgibbon, J.; Rouault-Pierre, K.; Caceres, J. F.

doi:10.1101/2022.05.26.492072

bioRxiv · 10.1101/2022.05.26.492072

A dual role for the RNA helicase DHX34 in NMDand pre-mRNA splicing and its function inhematopoietic differentiation

Hug, N.·Aitken, S.·Longman, D.·Raab, M.·Armes, H.·Mann, A. R.·Rio-Machin, A.·Fitzgibbon, J.·Rouault-Pierre, K.·Caceres, J. F.

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Abstract

The DExD/H-box RNA helicase DHX34 is a Nonsense-mediated decay (NMD) factor that together with core NMD factors co-regulates NMD targets in nematodes and in vertebrates. Here, we show that DHX34 is also associated with the human spliceosomal catalytic C complex. Mapping of DHX34 endogenous binding sites using Cross-Linking Immunoprecipitation (CLIP) revealed that DHX34 is preferentially associated with pre-mRNAs and locates at exon-intron boundaries. Accordingly, we observed that DHX34 regulates a large number of alternative splicing (AS) events in mammalian cells in culture, establishing a dual role for DHX34 in both NMD and pre-mRNA splicing. We previously showed that germline DHX34 mutations associated to familial Myelodysplasia (MDS)/Acute Myeloid Leukemia (AML) predisposition abrogate its activity in NMD. Interestingly, we observe now that DHX34 regulates the splicing of pre-mRNAs that have been linked to AML/MDS predisposition. This is consistent with silencing experiments in hematopoietic stem/progenitor cells (HSPCs) showing that loss of DHX34 results in differentiation blockade of both erythroid and myeloid lineages, which is a hallmark of AML development. Altogether, these data unveil new cellular functions of DHX34 and suggests that alterations in the levels and/or activity of DHX34 could contribute to human disease.

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Hug, N., Aitken, S., Longman, D., Raab, M., Armes, H., Mann, A. R., Rio-Machin, A., Fitzgibbon, J., Rouault-Pierre, K., Caceres, J. F.. 2022-05-26. A dual role for the RNA helicase DHX34 in NMDand pre-mRNA splicing and its function inhematopoietic differentiation. https://doi.org/10.1101/2022.05.26.492072

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