17.12.2018

Messung von Salinität und Sauerstoffgehalt in der Ostsee, Copyright: Universität Rostock/ITMZ

Phosphorus (P) and energy: The multifaceted roles and molecular mechanisms of P in cellular energy transductions
Prof. Dr. Inna Sokolova

Inhalt:
Phosphorus (P) is an essential element that plays a key role in metabolic and signaling processes of all organisms. The present talk will present the role of phosphorus as an energy storage and metabolic regulatory element in marine organisms and discuss the importance of P-mediated molecular mechanisms in environmental stress responses and tolerance of marine organisms. I will specifically focus on the role of phosphorus in energy transduction in mitochondria in the context of low oxygen (hypoxia) stress. Animal mitochondria are extremely sensitive to fluctuating oxygen levels such as occur during tissue ischemia and/or environmental hypoxia. In hypoxia-sensitive organisms, hypoxia and especially post-hypoxic reoxygenation cause mitochondrial injury due to the elevated production of reactive oxygen species, Ca2+ overload and damage to the mitochondrial membranes and enzymes; yet many hypoxia-tolerant species (including intertidal invertebrates) can endure frequent hypoxia-reoxygenation due to the diurnal and/or tidal oxygen cycles without apparent ill effects on mitochondrial integrity and function. The mechanisms of such exceptional mitochondrial robustness are not yet fully understood. I will discuss the mitochondrial responses to intermittent hypoxia in marine intertidal mollusks emphasizing the potentially adaptive functional and proteomic changes of the mitochondria as well as the modulation of cellular protection and stress response pathways (including antioxidant defense, autophagy and apoptosis) through transcriptional and reversible phosphorylation mechanisms that might contribute to high tolerance to fluctuating oxygen levels in these organisms. I will also discuss the current knowledge gaps with an outlook to future studies needed to shed light on mitochondrial adaptations to frequent oxygen fluctuations and evolution of metabolism in extremely variable environments as well as identify potential targets for future therapies to protect sensitive mammalian tissues from stress-induced injuries (e.g. during ischemia-reperfusion).

Referentin:
Frau Prof. Dr. Sokolova leitet seit 2016 die Professur für Meeresbiologie an der Mathematisch-Naturwissenschaftlichen Fakultät der Universität Rostock. Sie ist Expertin für Umweltphysiologie und Toxikologie von Meeresorganismen. Ihre Arbeitsgruppe untersucht Anpassungen von Meeresorganismen an Umweltstressoren und die Auswirkungen von Umweltveränderungen (sowohl natürlichen als auch anthropogenen) auf marine Populationen.

Veranstalter:
Agrar- und Umweltwissenschaftliche Fakultät (AUF), Gesellschaft der Freunde und Förderer der AUF und Wissenschaftsverbund IuK