Biology subjects

Majerova, E.

Publications and source records attributed to Majerova, E..

4 recordsLinked to original sources

bioRxiv2026

The Global Phosphorylation Landscape of Acute Heat Stress in Reef-Building Corals

Warming oceans disrupt the coral-algal symbiosis that sustains reefs, yet the signaling mechanisms initiating bleaching remain poorly understood. Integrating global phosphoproteomics across three reef-building corals with protein structure modeling revealed conservation between coral and human kinases, enabling inference of coral kinase activities and uncovering a shared signaling program induced by acute heat stress. Heat rapidly activated ERK, JNK, and p38 MAP kinases, suppressed cell cycle signaling, and remodeled pathways controlling chromatin, RNA processing, and metabolism. Most strikingly, thermal stress rewired immune receptor signaling networks associated with non-self recognition, suggesting that heat shifts the coral host from tolerance to immune recognition of its algal symbionts. These findings define conserved signaling mechanisms that precede bleaching, revealing actionable molecular targets for enhancing coral resilience.

systems biology↗

bioRxiv2026

Selective conservation of symbiont cell-surface glycans across generations in a vertically transmitting coral

Coral resilience under climate change depends on the stability of coral-Symbiodiniaceae symbioses. While vertically transmitting corals inherit symbionts directly from parental colonies, the extent to which symbiont cellular traits are conserved across life stages remains unclear. Here, we examined cell-surface glycan profiles of Symbiodiniaceae in parental colonies and eggs of the coral Montipora capitata. Glycan signatures were structured by symbiont genus and differed between life stages, with mannose/glucose- and galactose-containing glycoproteins as primary drivers of variation. Despite life-stage differences, parent-offspring comparisons revealed significant conservation of glycan profiles, indicating intergenerational transmission of symbiont cellular traits that differed between Cladocopium and Durusdinium and were driven by distinct glycan classes. These results suggest that vertical transmission preserves key recognition-relevant glycans while allowing flexibility in other symbionts surface traits, providing a mechanistic basis for symbiosis stability.

cell biology↗

bioRxiv2024

BAK knockdown delays bleaching and alleviates oxidative DNA damage in a reef-building coral

Climate change is rapidly pushing coral reefs towards extinction. Efforts to restore and protect these ecosystems using resilient corals are increasing, but our understanding of cellular mechanisms of thermal resilience and trade-offs remains limited. Here, we demonstrate downregulation of pa-BAK slows bleaching and stabilizes the symbiosis during acute heat stress in Pocillopora acuta. Counterintuitively, oxidative DNA damage - a hallmark of the thermal stress response in corals - was prevented in corals with such "forced" symbiosis stability, possibly through alterations in mitochondrial ROS release. Using expression data of genes representing various stress-response pathways, we propose a model that coral heat stress response is mediated via the AMPK/Foxo3/Nrf2 signaling network. Developing our understanding of heat-stress defense mechanisms promoting stability in the coral-algal symbiosis is fundamental for effective modern coral reef restoration practices based on improving system resilience.

molecular biology↗

bioRxiv2021

A BI-1 mediated cascade improves redox homeostasis during thermal stress and prevents oxidative damage in a preconditioned reef-building coral

Global coral reef decline is largely driven by the breakdown of the coral-algal symbiosis during temperature stress. Corals can acclimatize to higher temperatures, but the cellular processes underlying this ability are poorly understood. We show that preconditioning-based improvements in thermal tolerance in Pocillopora acuta are accompanied by increases in host glutathione reductase (GR) activity and expression, which prevents DNA damage. A strong correlation between GR and BI-1 expression in heat-stressed preconditioned corals and the presence of an antioxidant response element (ARE) in the GR promoter suggest BI-1 could regulate GR expression through Nrf2/ARE pathway. To fortify this link, we developed an siRNA- mediated gene knockdown protocol and targeted the coral BI-1 gene. BI-1 knock-down specifically decreased GR expression and activity and increased oxidative DNA damage in heat- stressed preconditioned corals, showing that BI-1-mediated enhanced antioxidant response during acute heat stress is a key mechanism that prevents oxidative DNA damage after preconditioning. TeaserPreconditioning improves redox homeostasis and prevents oxidative stress in a thermally stressed reef-building coral

cell biology↗