Biology subjects

Zecic, A.

Publications and source records attributed to Zecic, A..

4 recordsLinked to original sources

bioRxiv2026

A Neuronally Active Bacterial Siderophore Manipulates Host Behavior and Longevity

Aging populations face a growing burden of neurodegenerative disease and behavioral decline. The microbiota is increasingly implicated in host physiology, highlighting an urgent need to understand how gut microbes modulate brain function and late life health. Here, we develop a high-throughput microbe-host screening platform to systematically dissect how bacterial genes shape organismal behavior. Using the Escherichia coli Keio library of 3,985 distinct non-essential single-gene deletion mutants in combination with Caenorhabditis elegans, we quantitatively profiled 768 behavioral features per bacterial clone and uncovered a coherent module of bacterial genes involved in iron homeostasis that robustly reprogrammed host behavior. Bacterial omics analyses revealed that alterations in iron homeostasis amplify siderophore production in a TCA cycle-dependent manner, and loss of enterobactin biosynthesis abolished the bacteria-induced changes in worm movement. Transcriptional, molecular and functional studies demonstrated that bacterial enterobactin activates host neuromuscular responses to shape both lifespan and healthspan in a manner dependent on the mitochondrial unfolded protein response. Thermal proteome profiling identified mitochondrial glutaryl-CoA dehydrogenase and the electron-transfer flavoproteins A and B as enterobactin-binding targets that control mitochondrial function. Finally, genetic manipulation of neuronal mitochondrial and cytosolic reactive oxygen species via superoxide dismutase and catalase revealed that redox state modulates enterobactin-driven changes in movement and lifespan through the secretin-family GPCR neuropeptide receptor PDFR-1. Together, these findings establish microbial enterobactin as a non-canonical neurotransmitter regulating neuronal mitochondrial function, behavior and aging, defining a gut bacteria-brain axis with broad implications for maintaining late-life health.

animal behavior and cognition↗

bioRxiv2026

A protein language model unveils the E. coli pangenome functional landscape regulating host proteostasis

Understanding how bacterial diversity at strain level resolution shapes host physiology is a central challenge in microbiome research. The vast, functionally unknown genetic diversity within a species pangenome makes it difficult to connect genes to function and their impact on host physiology. Here, we explore how the functional landscape of the Escherichia coli pangenome impacts transcriptional responses in Caenorhabditis elegans and show that traditional gene-centric methods fail to provide significant functional associations with the host. Thus, we developed a pangenome framework that leverages the protein language model ProtT5 and generates unique strain embeddings representing the functional potential of each 9,558 E. coli isolate. Stratification of the pangenome into distinct functional guilds aligned with key host processes such as cell division, metabolism and proteostasis. Further, we identify a critical interplay between the extensive network of bacterial chaperones and proteases in regulating host proteostasis. We find that the bacterial chaperone DNAK/HSP70 and protease ClpX fine-tune the host ubiquitin-proteasome system by controlling propionate and vitamin B12 availability. These findings reveal a conserved co-proteostasis mechanism as a key phenomenon modulating host-microbe interactions through metabolic communication. Our pangenome-to-phenotype approach offers a powerful strategy to decode bacterial pangenome functional diversity, directly linking microbial genomic variation to host physiological outcomes.

systems biology↗

bioRxiv2023

SPTF-3/SP1 orchestrates mitochondrial biogenesis upon ribosomal stress and acute starvation

When cells have increased energy demand, they respond by elevating the production of new mitochondria through the process of mitochondrial biogenesis. This complex physiological undertaking requires precise coordination of mitochondrial and nuclear gene expression to extend the existing mitochondrial network in the cell. Using C. elegans as a model system we have identified stress-induced transcription factor SPTF-3 as a novel regulator of mitochondrial biogenesis on-demand upon increased heat stress, dietary restriction, and acute starvation. We show that SPTF-3 also regulates ATFS-1, the main transcriptional regulator of UPRmt (mitochondrial unfolded protein response). Thus, by orchestrating two parallel programs - mitochondrial biogenesis and UPRmt, SPTF-3 safeguards mitochondrial wellbeing and function upon stress, thus allowing survival in unfavorable conditions. Mitochondrial biogenesis is induced by disturbances in cytoplasmic ribosomal assembly, which leads to preferential translation of SPTF-3. Importantly, we demonstrated that the role of SPTF-3 in the regulation of mitochondrial biogenesis upon nutrient deprivation is conserved in mammals through its homolog SP1.

molecular biology↗

bioRxiv2021

Prediction of biological age by morphological staging of sarcopenia in Caenorhabditis elegans

Sarcopenia encompasses a progressive decline in allover muscle quantity and quality. Given its close association with aging, it may represent a valuable healthspan marker. Given the strong commonalities with human muscle structure and the facile visualization possibilities, C. elegans represents an attractive model for studying the relationship between sarcopenia and healthspan. However, classical assessment relies on visual scoring of muscle architecture, which is subjective and inaccurate. To resolve this, we have developed an automated image analysis pipeline for the detailed quantification and classification of muscle integrity in confocal microscopy images from a cohort of aging myosin::GFP reporter strains. We then extracted a variety of morphological descriptors and found a subset to scale linearly with age. This allowed us to establish a general linear model that predicts biological age from a morphological muscle signature. To validate the model, we evaluated muscle architecture in long-lived worms that are known to experience delayed sarcopenia by targeted RNAi-mediated knockdown of the daf-2 gene. We conclude that quantitative microscopy allows for staging sarcopenia in C. elegans and will be of use for systematic screening for pharmacological or genetic modulators that mitigate age-related muscle frailty and thus improve healthspan in C. elegans.

bioinformatics↗