Biggest News of the Week...Maybe

What is the biggest news of the week?  More dead in Iraq?  Hardly, except that Rumsfeld gets to make good on his promise to sign the letters to the families of the dead soldiers.  Bush is the Person of the Year?  Hardly.  Yes, he joins luminaries such as FDR, Eisenhower, and The Computer, but also Hitler, Gingrich, Stalin, and Khrushchev.  New version (0.9.1) of Damn Small Linux released.  No, although the GIMP 2.2 comes close.  The Castro-Chavez trade pact?  Maybe.  That could turn out to be really important.  My nomination for Biggest News of the Week is reported in Science Magazine, echoed by news@Nature.com and The-Scientist.com.

Authored by Solomon Snyder, et. al., Phosphorylation of Proteins by Inositol Pyrophosphates appears in Science (17 December 2004: 2101-2105.)  Dr. Snyder is a neuroscientist, sometimes referred to as "the father of synaptic chemistry."   From the review at The-Scientist:

Phosphorylation without ATP
IP7 offers a nonenzymatic alternative for adding phosphate to proteins
By Charles Q Choi

For the first time, scientists have described in this week's Science a way for cells to add phosphate groups to proteins that doesn't involve using adenosine triphosphate (ATP) as a donor.

"Nobody had ever dreamt you could phosphorylate with a donor other than ATP," said senior author Solomon Snyder at Johns Hopkins University in Baltimore, who, along with colleagues, suggested a decade ago that inositol pyrophosphates such as diphosphoinositol pentakisphosphate (IP7) might serve as phosphorylating agents due to their highly energetic pyrophosphate bonds.

"ATP phosphorylation has heretofore been regarded as the primary mode of all cellular signaling in biology," Snyder told The Scientist. "IP7 phosphorylation may be of comparable importance, with similarities but major differences—for instance, it is nonenzymatic. It may represent a new form of intracellular signaling." [...]

For decades, phosphorylation of proteins by ATP has been thought to be the central means of controlling the behavior of intracellular proteins.  The discovery of an alternative pathway could have profound implications.  It could even have therapeutic implications, for a wide range of diseases.  

Lately, I've been critical of science reporters who oversell the implications of the studies upon which they base their articles.  So I guess I better not do the same thing.  The fact is, there is a lot of research to be done, to figure out how important this mechanism really is, and how to control it, assuming that it turns out to be important.  To their credit, the reporters at news@Nature.com and The-Scientist.com were cautious about their interpretation.  From Nature: 

[...]Snyder speculates that interfering with IP7 might, one day, be used to treat certain diseases. If, for example, IP7 normally fires up a protein that triggers cancer, then blocking that activation could help fight the disease.

York counters that this is "a huge stretch". He and others in the field say they would like to see much more evidence before they are convinced that IP7 is as crucial in cell biology as ATP.

For example, scientists need to prove that IP7 adds phosphates to many more proteins than those demonstrated, and that this actually alters what they do in the cell. The IP7 discovery is not yet as big a deal as the ATP find, says York, "but maybe it'll just take time to figure out." [...]

Forget Bush, Rumsfeld, Iraq, and Castro.  I vote for nonenzymatic phosphorylation as the big news of the week. 

Big News of the Week...Maybe