Cells that “spit” out their contents and messenger RNA that is not so swift at delivering its message. Those are two brand new stories on our new and improved website. Check it out and let us know what you think.
The first story arose from a simple question: How do secretory cells – those that produce copious amounts of such substances as tears, saliva or all those bodily fluids – manage to get their contents out of the cell? Cells are walled all the way around; they don’t really have doors for letting things the size of a drop of fluid out. Instead, they use the vesicle system – small globes made of the same stuff as the cell membrane that transport the drops out to the edge. The vesicles then fuse with the membrane, releasing their cargo to the outside.
Prof. Ben-Zion Shilo and his group realized that this was all well and fine for small amounts of biochemicals, but secretory cells would need a better system. Their results, which involved a lot of intricate time-lapse observation in the saliva glands of fruit-fly larvae, are beautiful to watch as well as instructive.
Salivary gland of a larval fruit fly. Vesicles (red) carrying the glue must empty their contents quickly and efficiently
The second story arose from a surprising observation: Certain liver cells that are involved in metabolism seemed to have large amounts of messenger RNA in their nuclei. Why would RNA stick around in the cell nucleus, instead of rushing out to make proteins? Dr. Shalev Itzkovitz and his group followed up on this question by asking further questions: How many cells keep RNA in their nuclei? How long does this RNA tend to stay? Which genes produce the homebody RNA?
Although they have not yet answered every one of their questions, they have uncovered a new level of regulation in the cell – one that is not immediately intuitive.
Nuclei of liver cells, mRNA of certain genes in white
Revealing how some cells get rid of their contents or discovering that others hoard things deep within – neither finding will cure disease tomorrow. Both are changing our understanding of how the human cell functions, and both are going to contribute, in the future, to human health and welfare. We promise to keep bringing you these stories and more.
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