Tuesday, September 23, 2014

A new mechanism of gene regulation!

I love it when new things are discovered, especially if they concern biochemistry. I'm always on the lookout for exciting discoveries that are going to make it into the next edition of my textbook.

That's why my eyes lit up (not!) when I saw this headline in Biology New Net: New mechanism in gene regulation revealed. Here's the teaser ...
The information encoded in our genes is translated into proteins, which ultimately mediate biological functions in an organism. Messenger RNA (mRNA) plays an important role, as it is the molecular template used for translation. Scientists from the Helmholtz Zentrum Muenchen and the Technische Universität Muenchen, in collaboration with international colleagues, have now unraveled a molecular mechanism of mRNA recognition, which is essential for understanding differential gene regulation in male and female organisms. The results are published in the renowned scientific journal Nature.
It took me a few minutes to track down the article because there weren't many hints in the press release. Turns out it still hasn't appeared in the print copy but it's available online.
Hennig, J., Militti, C., Popowicz, G.M., Wang, I., Sonntag, M., Geerlof, A., Gabel, F., Gebauer, F., and Sattler, M. (2014) Structural basis for the assembly of the Sxl–Unr translation regulatory complex. Nature published online Sept. 7, 2014 [doi:10.1038/nature13693]
The "new mechanism" is the binding of a protein to mRNA to block translation.

I suppose it depends on your definition of "new." We've been teaching undergraduates about this for over thirty years.

There's nothing in the paper about a new mechanism of gene regulation and there's no evidence in the press release that any of the authors make such a claim.


  1. That's what you get for reading the tabloids...

  2. But seriously, while it doesn't *sound* particularly noteworthy, getting in Nature is a non-trivial task. I'm not particularly interested in metazoa, but maybe this is the first time this has been demonstrated in Drosophila or something like that?

    1. It's a very intetesting paper showing the structure of a complex of proteins that bind to to 3' end of an mRNA to inhibit translation. One of the players is the well-known Sxl gene product that regulates sex determination in Drosophila. It's a worthy Nature paper, just not a NEW mechanism of regulation. The authors never make that claim.

    2. As far as I understand it, the meat of the paper is that rather than having a single protein block mRNA, the combination of Sxl and Uhr does it, while either of them is not binding frequently enough, the combination binds more frequently. Now, I'm not a molecular biologist, so I wouldn't know how well this is documented, but it seems as if this is the key here, because you would usually get a linear relationship between the number of inhibitors and the number of translated mRNAs, but this allows a non-linear effect of multiple copies of the genes in question and thus a stable concentration of products.

      The second half of the press release as well as the paper seem to imply this interpretation - am I completely off?