Genome complexity: control of alternate start sites (Introduction)

by David Turell , Tuesday, July 17, 2018, 15:20 (2109 days ago) @ Balance_Maintained

Depending the start site the coding for protein may produce a different product:

https://phys.org/news/2018-07-hidden-rnas-protein-synthesis.html

"While scanning RNAs for the first AUG, the protein-making machinery frequently encounters sites that diverge from AUG by one building block (such as AUA). On occasion, protein synthesis starts from such alternative start sites. How the protein-making machinery chooses which alternative sites to use has been a mystery.

"In a new study published in Nature, scientists describe how the protein-making machinery identifies alternative initiation sites from which to start protein synthesis. "We discovered a mechanism that explains how sites are chosen for translation events that occur in regions that are traditionally considered untranslated and that initiate at non-traditional start sites," said senior author Eckhard Jankowsky, Ph.D. "Over the last several years it has become clear that translation in these regions is pervasive, but it is poorly understood how start sites are chosen among the millions of possible start sites."

David Comment: just another level of control which means one gene can make several different proteins.

Tony: And one that acts as a defensive mechanism for the cell, it seems. On one level, the one observed thus far, it prevents defective proteins from forming. However, the article methions that cells do this in response to viral targeting as well, which indicates to me that it might also be a low level part of the immune system. Could this be another level of viral intruder detection? If so, could the new proteins, the one generated from the alternative start site, actually act as a trigger for alerting the immune system that something got by them, and informing it of what they virus is targeting so that the immune system can respond appropriately?

Your thought makes sense.