Scientists provide new insight in the mitochondrial protein-lipid interactions.
(Dr. Nathan N. Alder with his team Members, Image: Ketan Malhotra)
Mitochondria are cell's powerhouses, which catalyze the conversion of the energy stored in nutrients into the production of ATP, the chemical energy currency of the cell. When mitochondrial function is compromised, it can lead to various complications related to the functioning of organs with high metabolic rates such as the brain and heart. This study has provided clues as to how deregulation of mitochondrial lipid homeostasis can contribute to mitochondrial diseases such as Barth syndrome.
The research labs at the University of Connecticut led by Prof. Nathan N. Alder from the Department of Molecular and Cell Biology with his team members, including Dr. Ketan Malhotra, Dr. Arnab Modak and many others- have identified precise roles of cardiolipin in the initial stages of mitochondrial protein import – namely, mediating crucial interactions between the protein substrate receptor and the protein import channel.
The results of this study were published in the scientific journal Science Advances.
Among the many roles of mitochondria, they are the primary producers of the “energy currency” of the cell; therefore, the proper functioning of these organelles is important for many cellular processes. Most mitochondrial proteins are made outside the organelle and are transported via the coordinated action of a set of molecular machines residing on its two membranes.
“Mitochondrial lipids – specifically cardiolipin – play a central role in maintaining cellular energy homeostasis, but their importance in mediating mitochondrial protein transport remains underappreciated. This study aimed to bridge that gap and understand how cardiolipin aids the process of protein transport into mitochondria,” said Dr. Ketan Malhotra, first author of this paper.
“Perhaps the most formidable challenge in coordinating this work was the highly multidisciplinary nature of this study, which included analyses that spanned from molecular biophysics up to the level of the cell,” said Dr. Alder.
This study has important implications in the area of medical research since it demonstrates how lipid homeostasis is important for mitochondrial biogenesis. This study has shown that patients suffering from Barth syndrome can have a deficient mitochondrial protein transport system. This new study has opened new perspectives to look deeper inside the protein transport system to develop better understanding and control measures for such complications.