Nuclei

Exeter team solves fungi cell mystery

A University of Exeter team of scientists has solved the puzzle of how fungi organise their nuclei, which contain their DNA. Their study is published in the internationally-leading Journal of Cell Biology.

The nucleus in each animal, plant or fungi cell controls cell function and survival by housing the organisms’ genomic information. The interior of the nucleus exchanges information, structural molecules and proteins with the cytoplasm of the cell. This is achieved via the nuclear pores, which act like gates within the outer membranes of the nucleus, called the ‘nuclear envelope’. The nuclear pores are evenly distributed over the nucleus to ensure the exchange is efficient.

Animal cells anchor the nuclear pores and chromosomes to a network of protein filaments, known as the nuclear lamina, within the interior of the nucleus. Although fungi are close relatives to animals, they do not posses such a network and until now scientists have not known how these important organisms organise their nuclear pores and chromosomes.

Using several fungal model systems, the Biosciences team led by Professor Gero Steinberg showed that the fungal nuclear pores and associated chromosomes are actively moving within the nuclear envelope. This movement is driven by molecular motors that use Adenosine-5'-triphosphate (ATP), a major ‘fuel’ in the cell, to move the pores along the fibres of the cytoskeleton.

The active movement of the nuclear pores and the attached chromosomes ensures firstly that the pores are evenly distributed within the fungal nuclear envelope. Secondly, it means that the chromosomes are properly arranged within the nucleus and thirdly that exchange between the nucleus and the cytoplasm occurs efficiently. Thus, the motility of fungal nuclear pores replaces the need of a structural nuclear lamina.

Professor Gero Steinberg said: “This project was motivated by curiosity and the outcome is a consequence of many people’s effort. It clearly shows us that important discoveries are still waiting to be made and that research is a team effort. There are many scientific findings that promise solutions to actual problems, while other discoveries are about the principles of life on Earth and they show us the beauty of nature. I am attracted by both, and despite the competitive nature of research, it is fun to be a scientist. A metaphor for my work would be a quest for treasure in a dungeon full of surprises, hidden doors and dragons.”

Watch the video produced by Ben Short for Cell Biology

Date: 3 August 2012

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