Centro Nacional de Investigaciones Cardiovasculares:

For decades, biologists assumed a cell’s energy simply diffused to wherever it was needed. It turns out the most important destination of all has a private delivery line An international team of scientists led by Dr. Ivan Menendez-Montes, Assistant Professor at the University of Arizona, and Dr. Hesham A. Sadek, Director of the Sarver Heart Center at the University of Arizona and Group Leader at the Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), has uncovered a previously unknown mechanism through which mitochondria directly supply energy to the cell nucleus.

Published in Nature, the study demonstrates that mitochondria, the power house of the cell, physically dock at control center of the cell, the nucleus, though its main gate – the nuclear pore complexes. This creates a highly efficient system for delivering energy and metabolites directly into the nucleus. Turns out that rather than flooding a house with heat and hoping it reaches every room, the system is more like running a dedicated power cable straight to the control center. The findings challenge the long-standing view that mitochondrial products, such as ATP, diffuse freely through the cytoplasm before reaching the nucleus.

Mitochondria and the nucleus are known to maintain a close functional relationship. The nucleus supplies proteins required for mitochondrial function, while mitochondria provide energy and metabolites essential for cellular activities. Until now, it was assumed that these mitochondrial products reached the nucleus through passive diffusion. The new study reveals that mitochondria and the nucleus have evolved a much more efficient mechanism.

Using advanced microscopy, proteomics, genetic engineering and animal models, the researchers discovered that mitochondria physically attach to the nuclear pore complex through an interaction between the mitochondrial protein VDAC1 and the nuclear pore protein RANBP2. This contact enables the direct delivery of energy-rich molecules to the nucleus, supporting processes such as gene regulation, chromatin remodeling, transcription and cellular differentiation. [Continue reading…]