Atabaki-Pasdar, N. | bioRxiv Science

bioRxiv2025

Energy Conservation Drives Adaptive Specialization Through Fine-tuned Organizations

Energy conservation is at the basis of evolutionary optimization in living systems. Yet, how cells maintain function during metabolic stress while preserving adaptive capacity remains unclear. Here, we use a functional genomics approach to identify metabolic human accelerated regions (mHARs) genomic hubs (evolutionarily tuned regions) in adipose tissue that coordinate adaptive responses to nutrient deficit. During fasting, cooperative regulators PGC1A, YY1, and CTCF activate these hubs, promoting chromatin contacts that regulate lipid cycling genes such as Dgat1 and Atg4c. This activation maintains lipid and pH homeostasis while limiting oxidative stress, thereby preserving cellular plasticity. When disrupted, nutrient-stress adaptations are impaired leading to metabolic dysfunction and glucose intolerance. This is driven by NCOA7, an oxidative stress mediator that impairs lysosome function and transcriptional plasticity, triggering an inflammatory response. In cellular models, this mechanism blocks pH-mediated PGC1A droplet plasticity, further inhibiting mHAR-genomic hub activity and metabolic homeostasis. Human adipocytes show enhanced transcriptional activity of these genomic hubs compared to murine cells, with multi-enhancer mHAR regulation suppressing disease-associated variants linked to ANGPTL3 and PCSK9. Loss of this cooperative plasticity shifts cells to maladaptive responses, activating STAT1-driven disease gene expression. Our findings reveal that investigating the contextual activity of evolutionary adaptations can uncover functional hubs critical for stress resilience. This also shows that cells exploit nutrient fluctuations to drive tunable transcriptional organizations that lead to durable adaptations, identifying actionable targets for metabolic disease. One-Sentence SummaryEvolutionary tuned nuclear compartments convert nutrient stress into adaptive transcriptional organizations that preserve plasticity and suppress metabolic disease.

physiology↗

bioRxiv2021

Metabolic resilience is encoded in genome plasticity

Metabolism plays a central role in evolution, as resource conservation is a selective pressure for fitness and survival. Resource-driven adaptations offer a good model to study evolutionary innovation more broadly. It remains unknown how resource-driven optimization of genome function integrates chromatin architecture with transcriptional phase transitions. Here we show that tuning of genome architecture and heterotypic transcriptional condensates mediate resilience to nutrient limitation. Network genomic integration of phenotypic, structural, and functional relationships reveals that fat tissue promotes organismal adaptations through metabolic acceleration chromatin domains and heterotypic PGC1A condensates. We find evolutionary adaptations in several dimensions; low conservation of amino acid residues within protein disorder regions, nonrandom chromatin location of metabolic acceleration domains, condensate-chromatin stability through cis-regulatory anchoring and encoding of genome plasticity in radial chromatin organization. We show that environmental tuning of these adaptations leads to fasting endurance, through efficient nuclear compartmentalization of lipid metabolic regions, and, locally, human-specific burst kinetics of lipid cycling genes. This process reduces oxidative stress, and fatty-acid mediated cellular acidification, enabling endurance of condensate chromatin conformations. Comparative genomics of genetic and diet perturbations reveal mammalian convergence of phenotype and structural relationships, along with loss of transcriptional control by diet-induced obesity. Further, we find that radial transcriptional organization is encoded in functional divergence of metabolic disease variant-hubs, heterotypic condensate composition, and protein residues sensing metabolic variation. During fuel restriction, these features license the formation of large heterotypic condensates that buffer proton excess, and shift viscoelasticity for condensate endurance. This mechanism maintains physiological pH, reduces pH-resilient inflammatory gene programs, and enables genome plasticity through transcriptionally driven cell-specific chromatin contacts. In vivo manipulation of this circuit promotes fasting-like adaptations with heterotypic nuclear compartments, metabolic and cell-specific homeostasis. In sum, we uncover here a general principle by which transcription uses environmental fluctuations for genome function, and demonstrate how resource conservation optimizes transcriptional self-organization through robust feedback integrators, highlighting obesity as an inhibitor of genome plasticity relevant for many diseases.

systems biology↗