(June 26, 2015) The transportation of certain molecules into and out of the cell nucleus takes place via nuclear pores. For some time, detailed research has been conducted into how these pores embedded in the nuclear envelope are structured. Now, for the first time, biochemists from the University of Zurich have succeeded in elucidating the structure of the transportation channel inside the nuclear pores in high resolution using high-performance electron microscopes.
An active exchange takes place between the cell nucleus and the cytoplasm: Molecules are transported into the nucleus or from the nucleus into the cytoplasm. In a human cell, more than a million molecules are transported into the cell nucleus every minute. In the process, special pores embedded in the nucleus membrane act as transport gates. These nuclear pores are among the largest and most complex structures in the cell and comprise more than 200 individual proteins, which are arranged in a ring-like architecture. They contain a transportation channel, through which small molecules can pass unobstructed, while large molecules have to meet certain criteria to be transported. Now, for the first time, an UZH research team headed by Professor Ohad Medalia has succeeded in displaying the spatial structure of the transport channel in the nuclear pores in high resolution.