Defining multifunctional roles for proteins in development and disease

Project Summary This proposal for the NIGMS R35 Early-Stage Investigator award seeks to support my laboratory’s overall mission of determining multifunctional roles for proteins involved in animal development and human health. This is important in genetic causes of disease, as a complete understanding of a protein’s cellular

functions is needed to design effective therapies. We combine the powerful genetic tools of Drosophila melanogaster with high resolution imaging to determine secondary functions of development and disease proteins. Our expertise in microcomputed tomography (μ-CT) is critical for these investigations, yet we have also

not harnessed the full potential of what this imaging technology can offer for model organism communities. This proposal encompasses two complementary themes to address these gaps in knowledge. Theme 1 describes our plans to use the Drosophila melanogaster protein Abnormal Spindle (Asp), who’s human ortholog (ASPM)

has been implicated in microcephaly, cancer, and infertility, as a model system to determine multifunctional protein roles and their influence on stem cell function, tissue size, and tissue architecture. We will address three questions over the next 5-years. (1) What are the secondary functions of clinically relevant proteins whose

genotype–phenotype relationship is unknown? We will investigate Asp as a regulator of the Notch signaling pathway based on our preliminary data, which strongly suggests that Asp may be a novel component of this critical cell fate determination pathway. (2) Are protein moonlighting functions cell type specific? Leveraging our

protein interaction data, we will explore Asp’s interaction with the mitotic protein Mushroom body defect (Mud) in the brain and germline to determine if the cell biological mechanisms these proteins promote in each tissue are dependent on their direct interaction. (3) How do alternative roles of proteins affect the ability of stem cells

to control tissue size and architecture? This will examine the role of mitotic timing in stem cells, which we found to be disrupted in asp mutant animals, and how this influences the ability of stem cell populations in the brain and gut to promote proper tissue growth and architecture. In Theme 2, we will use our expertise in μ-CT and

artificial intelligence (AI) to create modern, updated developmental atlases for the Drosophila melanogaster and Xenopus laevis model organism communities. These virtual repositories and AI tools will be freely accessible, allowing for in-depth investigations of the entire developmental time window in 2D and 3D. Both themes will be

bolstered by ongoing productive collaborations. Our overall vision is to provide key insights into the multifunctional roles of a disease-relevant protein, while establishing the framework for future work to build a μ-CT mutant image database to allow fly and frog researchers to identify new phenotypes for

their favorite genes. This will serve to accelerate the identification of secondary roles for other biomedically- relevant proteins, toward a greater understanding of gene function and the genotype-phenotype relationship.