Real-time monitoring of proteins in the nuclear pore complex

In human cells, the nucleus is enclosed by a structure called the nuclear pore complex (NPC). It acts as a 'gatekeeper' controlling the transport of molecules between the nucleus and the surrounding cytoplasm (the protein-containing ...

Nanocontainers introduced into the nucleus of living cells

An interdisciplinary team from the University of Basel in Switzerland has succeeded in creating a direct path for artificial nanocontainers to enter into the nucleus of living cells. To this end, they produced biocompatible ...

Nanoporous material nets contaminant from water

Barely visible material that looks like tiny grains of sand may hold the key to removing an invisible health threat that has contaminated water supplies across the country. Researchers at Pacific Northwest National Laboratory ...

Nuclear pore complex outer rings: No longer 'one size fits all'

In eukaryotic cells, the nucleus is walled off from the rest of the cell by the nuclear envelope. All transport into and out of the nucleus occurs via cylindrical channels called nuclear pore complexes (NPCs) that penetrate ...

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 ...

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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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