HMN 2025: How Protein AIFM1 emerges as a central coordinator of mitochondrial vitality metabolism

A collaborative study from the University of Cologne has uncovered how a key mitochondrial protein, AIFM1 (Apoptosis-Inducing Factor Mitochondria-Associated 1), acts as a central hub within the regulation of mobile vitality manufacturing.

The analysis, carried out by the groups of Professor Dr. Jan Riemer on the Institute of Biochemistry of the Faculty of Mathematics and Natural Sciences and Dr. Simon Pöpsel on the Center for Molecular Medicine Cologne (CMMC), has been published within the journal Molecular Cell beneath the title “Interaction with AK2A hyperlinks AIFM1 to mobile vitality metabolism.”

Combining cell biology, useful biochemistry and superior structural biology, the review focuses on AIFM1, a protein essential for the functioning of mitochondria—the cell’s energy-producing organelles. Mitochondria are chargeable for producing adenosine triphosphate (ATP), the first vitality foreign money in organic techniques. Proper mitochondrial operate is important for the well being of energy-demanding tissues such because the mind, coronary heart and muscle tissue.

Defects in mitochondrial processes can result in a spread of issues, collectively referred to as mitochondrial ailments, which can manifest as neurodegenerative situations, muscular issues or metabolic syndromes.

While AIFM1 was beforehand acknowledged for its roles in programmed cell dying and respiratory chain meeting, this analysis expands that understanding by mapping its community of interplay companions. Most prominently, interplay with parts of the MICOS complicated and adenylate kinase 2 (AK2) hyperlinks AIFM1 to the institution of mitochondrial morphology and upkeep of vitality homeostasis.

Using state-of-the-art cryo-electron microscopy (cryo-EM), the researchers visualized AIFM1 complexes in unprecedented element. The ensuing atomic models revealed how AIFM1 fulfills its roles as a central coordinator inside the mitochondria. The researchers confirmed that AIFM1 stabilizes AK2A by binding to its C-terminal tail and that it positions AK2A near ATP-transporting proteins and the ATP-generating ATP-synthase, thereby collectively contributing to growing the effectivity of mitochondrial vitality manufacturing.

“One of the review’s key findings is the invention of an interplay between AIFM1 and a variant of AK2A, an enzyme essential for sustaining the steadiness of adenine nucleotides reminiscent of ATP—the cell’s important vitality foreign money,” Dr. Pöpsel states.

“We visualized these protein complexes at excessive decision, enabling the development of detailed atomic models. Our findings not solely spotlight AIFM1’s position in supporting AK2A but in addition reveal its operate as a central molecular hub, interacting with different key regulators of mitochondrial vitality metabolism, together with MIA40, the MICOS complicated, ADP/ATP translocases, and ATP synthase,” Professor Riemer provides.