Role of DDX41 in HSC development and MDS/AML

DEAD-BOX解旋酶41(DDX41)是一种已知的核酸传感器，它有助于 干扰素对逆转录病毒的反应。DDX41属于RNA解旋酶家族，具有独特的 Dead/H box(Asp-Glu-Ala-Asp/His)结构域，其成员已被牵连到 翻译，核糖体生物发生，核质运输，细胞器基因表达和 前信使核糖核酸剪接。最近发现DDX41是一种家族性肿瘤抑制基因。 和散发性骨髓增生异常综合征/急性髓系白血病(MDS/AML)以及其他 恶性血液病。在MDS/AML中，DDX41被认为与剪接体相互作用 成分和改变剪接，导致肿瘤抑制基因失活或 基因异构体平衡的改变，尽管这是否通过蛋白质-RNA发生， 蛋白质-DNA或蛋白质-蛋白质的相互作用尚不清楚。我们最近开发出了一种具有 DDX41的花序等位基因，这将使我们能够首次研究DDX41的S在造血中的作用 发展转型。DDX41生殖系敲除基因在发育过程中先于E10死亡，但 杂合子基因敲除的小鼠是完全可行的，将被用来确定 这些小鼠会患上骨髓发育不良。我们还生成了条件淘汰法，删除了 造血干细胞(HSC)中的基因。HSC将用于研究DDX41的作用 在造血谱系分化中。对敲除的HSCs的RNA序列分析将是 以确定DDX41的丢失是否会导致基因表达改变或剪接缺陷。 HSCs将用野生型和突变型DDX41进行转导；特别是，我们将工程 患者来源的突变以及死亡和解旋酶区域的突变，以开始确定 这种蛋白质如何在发育和转化中发挥作用。我们打算用这些老鼠来 研究DDX41在HSC发育中的作用，并确定其作用机制 它调节髓系细胞的转化。这些研究可能会加深我们对 以及生成用于测试潜在疗法的模型系统。

Dead-box helicase 41 (DDX41) is a known sensor of nucleic acids that contributes to the interferon response to retroviruses. DDX41 belongs to a family of RNA helicases, with distinct DEAD/H box (Asp-Glu-Ala-Asp/His) domains, whose members have been implicated in translation, ribosome biogenesis, nuclear-cytoplasmic transport, organelle gene expression and pre-mRNA splicing. DDX41 was also recently identified as a tumor suppressor gene in familial and sporadic myelodysplastic syndrome/acute myeloid leukemia (MDS/AML), as well as other hematological malignancies. In MDS/AML, DDX41 is thought to interact with spliceosomal components and alter splicing, resulting in the inactivation of tumor suppressor genes or alterations in the balance of gene isoforms, although whether this occurs through protein-RNA, protein-DNA or protein-protein interactions is not known. We recently developed mice with a floxed allele of DDX41, which will allow us for the first time to study DDX41's role in hematopoietic development and transformation. DDX41 germline knockouts die prior to E10 in development, but mice heterozygous for the knockout are completely viable and will be used to determine whether these mice develop myelodysplasias. We have also generated conditional knockouts that delete the gene in hematopoietic stem cells (HSC). The HSCs will be used to study the role of DDX41 in hematopoietic lineage differentiation. RNA Seq analysis on the knockout HSCs will be performed, to determine if loss of DDX41 results in altered gene expression or splicing defects. The HSCs will be transduced with wild type and mutant DDX41; in particular, we will engineer patient-derived mutations as well those in the DEAD and helicase domains, to begin to determine how this protein functions in development and transformation. We propose to use these mice to study the role of DDX41 in HSC development, as well as to determine the mechanism by which it regulates transformation of myeloid cells. These studies are likely to further our understanding of AML as well as to generate a model system for testing potential therapeutics.