The clouds of spaghetti that keep DNA data safe

Cells can avoid "data breaches" when letting signaling proteins into their nuclei thanks to a quirky biophysical mechanism involving a blur of spaghetti-like proteins, researchers from the Rockefeller University and the Albert ...

Scientists map the portal to the cell's nucleus

Like an island nation, the nucleus of a cell has a transportation problem. Evolution has enclosed it with a double membrane, the nuclear envelope, which protects DNA but also cuts it off from the rest of the cell. Nature's ...

Team discovers new mechanisms for DNA stability

Researchers from the University of Seville at the Andalusian Centre for Molecular Biology and Regenerative Medicine have discovered that in eukaryotic cells, the proximity of the genes to the pores in the nuclear membrane ...

How shuttling proteins operate nuclear pores

Nuclear pore complexes are tiny channels where the exchange of substances between the cell nucleus and the cytoplasm takes place. Scientists at the University of Basel report on startling new research that might overturn ...

Colon cancer nuclear pore dynamics are captured by HS-AFM

One of the key reasons for cancer mortality is the highly invasive behaviour of cancer cells, which is often due to aggressive metastasis. Metastasis is facilitated by various growth factors and cytokines secreted from cells ...

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Nuclear pore

Nuclear pores are large protein complexes that cross the nuclear envelope, which is the double membrane surrounding the eukaryotic cell nucleus. There are about on average 2000 nuclear pore complexes in the nuclear envelope of a vertebrate cell, but it varies depending on cell type and throughout the life cycle. The proteins that make up the nuclear pore complex are known as nucleoporins. About half of the nucleoporins typically contain either an alpha solenoid or a beta-propeller fold, or in some cases both as separate structural domains. The other half show structural characteristics typical of "natively unfolded" proteins, i.e. they are highly flexible proteins that lack ordered secondary structure. These disordered proteins are the FG nucleoporins, so called because their amino-acid sequence contains many repeats of the peptide phenylalanine—glycine.

Nuclear pores allow the transport of water-soluble molecules across the nuclear envelope. This transport includes RNA and ribosomes moving from nucleus to the cytoplasm and proteins (such as DNA polymerase and lamins), carbohydrates, signal molecules and lipids moving into the nucleus. It is notable that the nuclear pore complex (NPC) can actively conduct 1000 translocations per complex per second. Although smaller molecules simply diffuse through the pores, larger molecules may be recognized by specific signal sequences and then be diffused with the help of nucleoporins into or out of the nucleus. This is known as the RAN cycle. Each of the eight protein subunits surrounding the actual pore (the outer ring) projects a spoke-shaped protein into the pore channel. The center of the pore often appears to contains a plug-like structure. It is yet unknown whether this corresponds to an actual plug or is merely cargo caught in transit.

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