With this new function, Mitofusin 2 becomes a viable target to intervene in diseases such as neurodegeneration and cancer.
In the image, the ER of a cell with the Mfn2 protein (left) and without it. On the right, the ER form vesicles which indicates that the organelle is completely disorganized and unable to respond correctly to cellular stress (JP Muñoz)
Each cell in an organism has a sensor that measures the health of its "internal" environment. This "alarm" is found in the endoplasmic reticulum (ER), which is able to sense cellular stress and trigger either rescue responses or the death of the cell. A team from the Institute for Research in Biomedicine (IRB), in Barcelona, has discovered that the protein Mitofusin 2 (Mfn2) plays a crucial role in correctly measuring stress levels, and also makes sure the pathways of cell repair or cell death are effective.
The researchers reveal some of the molecular mechanisms that connect Mfn2 to endoplasmic reticulum stress in the latest edition of the scientific journal, EMBO Journal, from the Nature Group, published by the European Molecular Biology Organization.
When the scientists removed Mfn2 from the cell under conditions of cell stress, the endoplasmic reticulum responded by over-activating the repair pathways. By doing so, it contradictorily functioned worse, reducing the capacity of cells to overcome the stress insult and promoting to a lesser degree apoptotic cell death. “When Mfn2 is removed, the cellular stress response pathways are completely disrupted,” says Antonio Zorzano, coordinator of IRB’s Molecular Medicine Programme and leader of the group “Heterogenic and polygenic diseases".
Not only diabetes
Mfn2 is a mitochondrial protein whose deficiency is related to diabetes. In an earlier publication in Proceedings of the National Academy of Sciences (PNAS), Dr. Zorzano’s research team demonstrated that without Mfn2, tissues become resistant to insulin, a characteristic of diabetes and the so-called metabolic syndrome. In this study, they also observed that the cells had higher endoplasmic reticulum stress.
The current study investigates the relationship between mitochondria and the endoplasmic reticulum, and indicates that changes in mitochondria, caused by the loss of the Mfn2 protein, directly affect the endoplasmic reticulum function. “We have shown that Mfn2 is important for cell viability and has implications for numerous diseases, such as neurodegeration, cancer, cardiovascular disease, in addition to diabetes,” says postdoctoral researcher Juan Pablo Muñoz, first author of the study.
Is Mitofusin 2 a good therapeutic target?
“The fact that we can modulate cell damage response with Mfn2 opens a wide window of possible therapeutic avenues for further study,” says Muñoz. The Chilean scientist at IRB explains that tumour cells don’t activate cell death properly and proliferate uncontrolled. “Cancer cells have already been noted to have low Mfn2 levels, and if we could increase such levels, we would be able to promote apoptosis,” he continues. According to this, other research teams have already published work indicating that the overexpression of Mfn2 induce apoptosis.
To demonstrate the utility of Mfn2 as a target, the researchers now need to find a small molecule, or drug, that modulates its expression in animals. “Our work published on Mfn2 is a proof of concept that highlights the importance of this mitochondrial protein for cell health,” says Zorzano. One of the challenges of the group is to secure funding to perform a massive screening of molecules with the ability to modulate Mfn2 expression and confirm its effects in mice.Reference article:
The EMBO Journal (2013) 32, 2348 - 2361. doi:10.1038/emboj.2013.168
Sònia Armengou | EurekAlert!
Pathogenic bacteria hitchhiking to North and Baltic Seas?
22.07.2016 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Unconventional quasiparticles predicted in conventional crystals
22.07.2016 | Max-Planck-Institut für Chemische Physik fester Stoffe
Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.
Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...
Breakup of continents with two speed: Continents initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. The final speed can be up to 20 times faster than in the first, slow extension phase.phases
Present-day continents were shaped hundreds of millions of years ago as the supercontinent Pangaea broke apart. Derived from Pangaea’s main fragments Gondwana...
Scaffolding and specialised workers help with the delivery – Heidelberg biochemists gain new insights into biogenesis
A type of scaffolding on which specialised workers ply their trade helps in the manufacturing process of the two subunits from which the ribosome – the protein...
Scientists at the Helmholtz Zentrum München have developed a new mass spectrometry imaging method which, for the first time, makes it possible to analyze hundreds of metabolites in fixed tissue samples. Their findings, published in the journal Nature Protocols, explain the new access to metabolic information, which will offer previously unexploited potential for tissue-based research and molecular diagnostics.
In biomedical research, working with tissue samples is indispensable because it permits insights into the biological reality of patients, for example, in...
Chemists at the University of Basel have succeeded in using computer simulations to elucidate transient structures in proteins. In the journal Angewandte Chemie, the researchers set out how computer simulations of details at the atomic level can be used to understand proteins’ modes of action.
Using computational chemistry, it is possible to characterize the motion of individual atoms of a molecule. Today, the latest simulation techniques allow...
15.07.2016 | Event News
15.07.2016 | Event News
11.07.2016 | Event News
22.07.2016 | Information Technology
22.07.2016 | Physics and Astronomy
22.07.2016 | Life Sciences