Not exact matches
DNA never leaves the
nucleus of the cell; its molecular recipes are read
out in the form
of messenger RNA, which leaves the
nucleus and enters the cytoplasm, where
proteins are made.
RNA messages are copies
of small snippets
of DNA that move
out of the cell
nucleus to be converted into
proteins.
When Gillian Bates at Guy's Hospital, London and Stephen Davies at University College in London and their colleagues examined the brains
of transgenic mice endowed with a DNA encoding 150
of these glutamine repeats, they found that the
protein started
out, at birth, in the cytoplasm
of the animals» brain cells and then gradually migrated to cell
nuclei and clumped there.
Next, Grima looked at cell death in cultured neurons with a healthy or a mutant form
of Huntingtin, or with a mutant form
of Huntingtin that was treated with small amounts
of an experimental drug called KPT - 350, one that prevents a nuclear export
protein, Exportin - 1, from shuttling
proteins and RNA
out of the
nucleus.
RNA was once thought to be a mere middleman, carrying genetic messages from the DNA in the
nucleus out to cellular structures called ribosomes, where it directs the production
of proteins.
In the inherited form researched in the current study, this includes a deficiency
of the
protein progranulin, which is tied to the mislocalization
of another crucial
protein, TDP - 43, from the
nucleus of the cell
out to the cytoplasm.
This process, known as gene expression, begins with transcription, in which a molecule called messenger RNA transfers the information in DNA
out of the cell's
nucleus and into the cytoplasm, where it is translated into amino acids that form
proteins.
The RNA strand is then moved
out of the
nucleus where enzyme - like organelles called ribosomes use it as a guide to synthesize chains
of amino acids that form the desired
protein.