Related Experiment Video
Updated: Aug 24, 2026

An Improved Method to Isolate Mitochondrial Contact Sites
Published on: June 16, 2023
Intimate contacts of mitochondria with nuclear envelope as a potential energy gateway for nucleo-cytoplasmic mRNA
1Cancer Research Institute, Slovak Academy of Sciences, Bratislava 37, Slovakia. jarmil.prachar@savba.sk
Abstract:
The aim of the present study was to show that close contacts of mitochondria with nuclear envelope need not be just an accidental situation in the cell, but that such contacts could serve for flow of energy from a place of origin directly to a place of consumption. Mitochondria in close proximity to the nuclear envelope can be found virtually in all metabolically active cells. We used transmission electron microscopy to demonstrate this entity in different leukemia cells of human origin (patient's blood) and in mouse leukemia cell line. At high resolution, not only close proximity but even fusion of mitochondrial and nuclear membranes can be seen. Based on available data about mRNA transport through the nuclear pore complex and observed contacts of mitochondria with nuclei, we hypothesize that such contacts can provide a gateway for energy delivery to power mRNA export from the nucleus to the cytoplasm. Hence the lumen of the nuclear envelope can serve for transport or even storage of macroergic molecules in a manner similar to sarcoplasmic reticulum in fast-twitch skeletal muscles.
Related Concept Videos
Translocation of Proteins into the Mitochondria
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Mitochondrial Protein Sorting
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
Protein Transport into the Inner Mitochondrial Membrane
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Energy to Drive Translocation
Generally, polypeptides are unfolded by two distinct...
Mitochondrial Membranes
Mitochondrial Membranes
