Seminar: Variable OXPHOS efficiency in skeletal muscle: Proton leaks, ROS and glutathione redox

With Professor Mary-Ellen Harper, Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa.

Abstract

Oxidative phosphorylation (OXPHOS) is estimated to account for roughly 90% of cellular ATP production, though this can vary between cell types, metabolic conditions, and disease states.  The efficiency of ATP production by OXPHOS is highly variable, and efficiency can be expressed as units ATP produced per unit of substrate oxidized, or as units ATP produced per unit of oxygen consumed. 

Efficiency of OXPHOS is affected by site of electron entry into the electron transport system.  It also is greatly affected by proton leak uncoupling, and other routes of proton return to the mitochondrial matrix. Proton leak has poorly understood mechanisms, but includes the uncoupling proteins and the adenine nucleotide translocator (ANT). Beyond decreasing the efficiency of OXPHOS, proton leak can decrease the emission of reactive oxygen species (ROS) from the electron transport system by lowering protonmotive force. High levels of ROS can cause damage to cellular lipids, proteins, DNA and RNA. However low levels of ROS are important in cell signaling processes.

Glutathione is the major non-protein antioxidant in cells and in mitochondria. It also plays important roles in the post-translational modification of protein thiols, and this can protect the proteins from further damage, and can modify the function of the proteins. The latter concepts will be covered in this seminar, and experimental findings from studies of mouse and human skeletal muscles will be presented.

Also presented will be findings from our clinical translational studies which demonstrate the importance of skeletal muscle OXPHOS in diet-sensitive versus diet-resistant obesity.

Time and programme

7 December 2018

14:00-15:00: Seminar and discussion
15:00-16:00: Post seminar servings and socializing

Place 

Auditorium 1, August Krogh Building, Universitetsparken 13, DK-2100 Copenhagen.

For more information about this event and registration, please click here.