SPS1 deficiency-triggered PGRP-LC and Toll expression controls innate immunity in Drosophila S2 cells

Comprehensive analysis of orthologous genes reveals functional dynamics and energy metabolism in the rhizospheric microbiome of Moringa oleifera

Moringa oleifera, known for its nutritional and therapeutic properties, exhibits a complex relationship with its rhizospheric soil microbiome. This study aimed to elucidate the microbiome's structural composition, molecular functions, and its role in plant growth by integrating Clusters of Orthologous Genes (COG) analysis with enzymatic functions previously identified through KEGG, CAZy, and CARD databases. Metagenomic sequencing and bioinformatics analysis were performed from the rhizospheric soil microbiome of M. oleifera collected from the Mecca district in Saudi Arabia. The analysis revealed a role for the rhizospheric microbiome in energy production, storage, and regulation, with glucose serving as a crucial precursor for NADH synthesis and subsequent ATP production via oxidative phosphorylation. Key orthologous genes (OGs) implicated in this process include NuoD, NuoH, NuoM, NuoN, NuoL, atpA, QcrB/PetB, and AccC. Additionally, OGs involved in ATP hydrolysis, such as ClpP, EntF, YopO, and AtoC, were identified. Taxonomic analysis highlighted Actinobacteria and Proteobacteria as the predominant phyla, with enriched genera including Blastococcus, Nocardioides, Streptomyces, Microvirga, Sphingomonas, and Massilia, correlating with specific OGs involved in ATP hydrolysis. This study provides insights into the molecular mechanisms underpinning plant-microbe interactions and highlights the multifaceted roles of ATP-dependent processes in the rhizosphere. Further research is recommended to explore the potential applications of these findings in sustainable agriculture and ecosystem management.

Anti-Tumor Effects of Cecropin A and Drosocin Incorporated into Macrophage-like Cells Against Hematopoietic Tumors in Drosophila mxc Mutants

Five major antimicrobial peptides (AMPs) in Drosophila are induced in multiple sex combs (mxc) mutant larvae harboring lymph gland (LG) tumors, and they exhibit anti-tumor effects. The effects of other well-known AMPs, Cecropin A and Drosocin, remain unexplored. We investigated the tumor-elimination mechanism of these AMPs. A half-dose reduction in either the Toll or Imd gene reduced the induction of these AMPs and enhanced tumor growth in mxcmbn1 mutant larvae, indicating that their anti-tumor effects depend on the innate immune pathway. Overexpression of these AMPs in the fat body suppressed tumor growth without affecting cell proliferation. Apoptosis was promoted in the mutant but not in normal LGs. Conversely, knockdown of them inhibited apoptosis and enhanced tumor growth; therefore, they inhibit LG tumor growth by inducing apoptosis. The AMPs from the fat body were incorporated into the hemocytes of mutant but not normal larvae. Another AMP, Drosomycin, was taken up via phagocytosis factors. Enhanced phosphatidylserine signals were observed on the tumor surface. Inhibition of the signals exposed on the cell surface enhanced tumor growth. AMPs may target phosphatidylserine in tumors to induce apoptosis and execute their tumor-specific effects. AMPs could be beneficial anti-cancer drugs with minimal side effects for clinical development.

The selenophosphate synthetase family: A review

Selenophosphate synthetases use selenium and ATP to synthesize selenophosphate. This is required for biological utilization of selenium, most notably for the synthesis of the non-canonical amino acid selenocysteine (Sec). Therefore, selenophosphate synthetases underlie all functions of selenoproteins, which include redox homeostasis, protein quality control, hormone regulation, metabolism, and many others. This protein family comprises two groups, SelD/SPS2 and SPS1. The SelD/SPS2 group represent true selenophosphate synthetases, enzymes central to selenium metabolism which are present in all Sec-utilizing organisms across the tree of life. Notably, many SelD/SPS2 proteins contain Sec as catalytic residue in their N-terminal flexible selenium-binding loop, while others replace it with cysteine (Cys). The SPS1 group comprises proteins originated through gene duplications of SelD/SPS2 in metazoa in which the Sec/Cys-dependent catalysis was disrupted. SPS1 proteins do not synthesize selenophosphate and are not required for Sec synthesis. They have essential regulatory functions related to redox homeostasis and pyridoxal phosphate, which affect signaling pathways for growth and differentiation. In this review, we summarize the knowledge about the selenophosphate synthetase family acquired through decades of research, encompassing their structure, mechanism, function, and evolution.