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Jalal, M. S.

Publications and source records attributed to Jalal, M. S..

2 recordsLinked to original sources

Integrative Computational and Experimental Analysis of Curly Su Mutations in Drosophila melanogaster

The Curly Su (dMPO) protein, a homolog of the human myeloperoxidase (hMPO), is critical for wing development in Drosophila melanogaster. Like human peroxidases, dMPO is involved in various cellular and physiological processes, producing significant quantities of reactive oxygen species that contribute to both development and immunity in the fruit fly. Given the significant sequence and structural similarities between dMPO and hMPO, dMPO serves an ideal model for studying peroxidase functions and related pathologies. We performed saturated computational mutagenesis on dMPO, analyzing the effects of 11,191 missense mutations on its stability. Notably, the G378W mutation exhibited the greatest destabilizing effect, while the W621R, potentially pathogenic, also reduced dMPO stability. To investigate these effects in vivo, we used genome editing to generate the transgenic Drosophila with G378W, W621R, and deletion of residues 305-687. Remarkably, G378W mutants displayed significant alterations in wing morphology and reduced lifespan. RNA-seq analysis of transgenic and wild-type flies revealed differentially expressed genes (DEGs), as interpreted through gene ontology analysis. Our integrated computational and genetic approach identified dMPO mutations that disrupt protein stability and alter gene expression. These findings offer new insight into how single-point mutations can lead to systemic biological changes. Author SummaryProteins are the molecular machines that drive almost every process in living organisms, and even small genetic changes can disrupt their structure and function. In this study, we focused on Curly Su, a protein in fruit flies that is similar to human myeloperoxidase. We used a computational approach called saturation mutagenesis to model over 11,000 possible single mutations in the Curly Su protein and predict how they would affect its stability. We then used genome editing to introduce several destabilizing and potential disease-causing mutations into flies. These mutant flies developed abnormal wings, had shorter lifespans, and showed widespread changes in gene activity, particularly in metabolism and immune pathways. By combining computational predictions with experimental validation, our work demonstrates a powerful and generalizable strategy for linking specific genetic mutations to whole-organism outcomes. This approach not only sheds light on the biological role of Curly Su but also provides a framework that can be applied to other genes and organisms, offering insights relevant to human health and disease.

bioinformatics↗

Spargel/dPGC-1 influences cell growth through the E2F1-mediated endocycle pathway.

The endocycle is a specialized variant of the eukaryotic cell cycle program observed in various tissues across diverse organisms ranging from insects to mammals. The endocycle promotes cellular growth by alternating between the synthesis (S) and gap (G) phases, completely bypassing mitosis (M phase). E2F1 serves as a master regulator of the endocycle in Drosophila salivary glands, whereas the TOR signaling pathway controls the levels of the E2F1 protein post-transcriptionally. Cellular growth in tissues that undergo the endocycle is also dependent on nutrient availability. Drosophila Spargel (dPGC-1) is orthologous to a group of transcriptional co-activators in vertebrates known as PGC-1. In flies, Spargel influences cell growth through the Insulin signaling pathway via TOR. However, the mechanisms by which Spargel regulates endocycle-mediated growth have yet to be established. Here, we report an essential role of Spargel in the Drosophila larval salivary gland, which influences E2F1-mediated cellular growth. To elucidate the role of Spargel in the salivary gland, we performed FLP/FRT-mediated clonal analysis and found that a cell-specific loss of Spargel leads to smaller nuclei with reduced DNA content due to the early termination of DNA replication. Further, the selective absence of Spargel abrogates the expression of a key DNA replication factor called E2F1, which promotes G1[->]S transition in endocycle. Thus, mechanistically, Spargel plays a key role in cell growth by positively influencing the endocycle process through the E2F1 pathway.

developmental biology↗