Poster abstracts
Poster number 158 submitted by Sarah Liu
The Belle dependent post-transcriptional regulation of centrosomal genes
Sarah Liu (Department of Physiology and Cell Biology, The Ohio State University), Junnan Fang (Department of Physiology and Cell Biology, The Ohio State University)
Abstract:
DDX3X syndrome is a neurodevelopmental disorder with intellectual disability and developmental delays, often caused by pathogenic variants in the DDX3X gene. DDX3X encodes DDX3 protein, a DEAD-box RNA helicase involved in regulating RNA transcription and translation. In humans, the homolog DDX3, is demonstrated to localize to the centrosome as a key transcription and translation regulator. Mutations or depletion in DDX3 have been shown to disrupt bipolar spindle formation, resulting in chromosome misalignment and poor segregation. Similarly, in Drosophila, the mutation of homolog, Belle, leads to chromosome mis-segregation and embryo unviability. However, it is relatively unknown whether Belle interacts with the centrosome and regulates centrosome activity through its role in RNA binding or another mechanism. With emerging evidence suggesting a connection between the centrosome and RNA localization, we hypothesize that Belle regulates centrosome activity through its role in RNA processing or translation of centrosome-associated mRNAs. To examine Belle's molecular functions, we are pursuing complementary in vivo and in vitro approaches. We recently generated transgenic fruit fly lines expressing Flag-tagged Belle controlled by an upstream activating sequence (UAS). These flies were crossed to maternal GAL4 drivers to drive Belle expression in ovaries, and FLAG-tagged Belle protein expression was validated by Western blot. Additionally, we employed ligation-independent cloning (LIC) to construct plasmids for recombinant Belle expression and purification in E. coli. These constructs will enable both biochemical assays of Belle helicase activity and identification of potential RNA or protein interaction partners in vivo and in vitro. We aim to uncover novel post-transcriptional mechanisms of how Drosophila Belle regulates centrosome activity during embryogenesis and neurodevelopment, which might be involved in human DDX3X syndrome.
References:
Fang, J., Tian, W., Quintanilla, M. A., Beach, J. R., & Lerit, D. A. (2025). The PCM scaffold enables RNA localization to centrosomes. Molecular Biology of the Cell, 36(6), ar75. https://doi.org/10.1091/mbc.E25-03-0117
Liao, S. E., Kandasamy, S. K., Zhu, L., & Fukunaga, R. (2019). DEAD-box RNA helicase Belle posttranscriptionally promotes gene expression in an ATPase activity-dependent manner. RNA (New York, N.Y.), 25(7), 825–839. https://doi.org/10.1261/rna.070268.118
Kotov, A. A., Godneeva, B. K., Olenkina, O. M., Adashev, V. E., Trostnikov, M. V., & Olenina, L. V. (2020). The Drosophila RNA Helicase Belle (DDX3) Non-Autonomously Suppresses Germline Tumorigenesis Via Regulation of a Specific mRNA Set. Cells, 9(3), 550. https://doi.org/10.3390/cells9030550
Keywords: Drosophila, Centrosome, RNA helicase