Lately, creationist rhetoric seems to increasingly mention the idea that if scientists really understood evolution, life, and biology, then why don’t they just create it themselves, as a kind of proof of concept? This rhetoric usually includes a statement like: “They can’t even create a simple cell … ”
This is very annoying, and displays either creationists’ excellent ability to frame their arguments or their utter stupidity. In fact, a cell is the most complicated thing going in biology. A cell is more complicated than an organism that is made up of cells, assuming that you don’t count the complexity of individual cells in that measure. An ecosystem is simple compared to a cell.
Proof of this complexity, confounded by unimaginable smallness of cells and their parts, is the steady pace of discovery of how cells actually work. The most recent finding is from Brown University and it relates to signal transduction. Signal transduction is the means by which cells communicate.
An important part of signal transduction is changing the function of specific proteins so that they either do or do not affect some other protein down the line in a cascade of events. One of the more common ways in which this is done in cell signaling is phosphorylation, in which proteins involved with cell receptors are altered such that the receptors turn on and off. One of the most common phosphorylation process related to signal transduction is known as “Tyrosine phosphorylation” which involves adding a little molecule to a protein in a way that significantly changes the way the protein folds itself up, and thus, how the protein functions (because at this scale, shape equals function). It may have the effect of closing a door or window in the case of a receptor site, but it does so by messing up the door or window so it just becomes part of the wall, in a sense.
While tyrosine phosphorylation is not by any means the most common phosphorylation, it is easy to isolate the phosphorylated molecules, so they are heavily studied.
An important process is when phosphorylation of receptor sites leads to a cascade of events that ultimately changes gene expression and thus, depending on circumstances, an appropriate immune response. The newly reported research identifies a previously not understood step, acetylation, in this cascade of events. Acetylation is a key part of the process, and if it does not happen, then there is no immune response.
It is not like acetylation was not previously known. Acetylation is just like phosphorylation … but instead of adding a phosphorus group to a protein, an acetyl group is added to the protein, again, changing its shape and thus its function. What this new research shows is that there is an acetylation step that is critical in a particuar immune response. Yet one more tiny, yet important part of the very complex workings of a cell is thus identified.