Oncology & Cancer

Nuclear gatekeeper could block undruggable prostate cancer targets

Certain molecular drivers of cancer growth are "undruggable—it's been nearly impossible to develop chemicals that would block their action and prevent cancer growth. Many of these molecules function by passing cancer-promoting ...

Immunology

Nuclear pore functions are essential for T cell survival

Nuclear pore complexes in the nuclear membrane not only control the transport of molecules into and out of the nucleus—they play an essential role in the survival of T cells. A new study by Sanford Burnham Prebys Medical ...

Genetics

Multifunctional protein contributes to blood cell development

Like an actor who excels at both comedy and drama, proteins also can play multiple roles. Uncovering these varied talents can teach researchers more about the inner workings of cells. It also can yield new discoveries about ...

Medical research

Why some developing hearts can't tell left from right

When a developing heart can't tell left from right, it can take a team of scientists from a host of disciplines to explain why. Yale pediatricians, geneticists, cell biologists, and imaging experts have identified a surprising ...

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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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