Stupid Evolution Quote of the Week
This week’s entry has a little jargon in it, but if you remember what we’ve said about the tRNA synthetase family of proteins (see 05/26/2004, 07/21/2003 and 06/09/2003 headlines), you’ll get it. Paul Schimmel and Karla Ewalt comment in Cell1 on new discoveries by Sampath et al.2 that two of these synthetases fuse together to regulate the inflammation reaction:
Aminoacyl tRNA synthetases are ancient proteins that appeared before the split of the tree of life into its three great kingdoms—archae [sic], eukarya, and bacteria. The 20 enzymes—one for each amino acid—catalyze aminoacylation of tRNAs and thereby establish the rules of the genetic code by associating each amino acid with a nucleotide triplet (the anticodon of the tRNA). The transition from the RNA world to the theater of proteins was thus made possible by the development of specific aminoacylation reactions. While the central connection between synthetases and the code has long been recognized, the modern enzymes have surprised us with novel functions beyond aminoacylation. They are key regulators and active components in a wide range of cellular functions from RNA splicing and transcription to apoptosis and angiogenesis….
…. we now see that tRNA synthetases in mammalian cells have more diverse and comprehensive connections to the inflammatory system than was previously appreciated. The diverse functions of these essential enzymes never cease to amaze!
1Paul Schimmel and Karla Ewalt, “Translation Silenced by Fused Pair of tRNA Synthetases,” Cell, Volume 119, Issue 2, 15 October 2004, Pages 147-148, doi:10.1016/j.cell.2004.10.001.
2Sampath et al., “Noncanonical Function of Glutamyl-Prolyl-tRNA Synthetase Gene-Specific Silencing of Translation,” Cell, Volume 119, Issue 2, 15 October 2004, Pages 195-208, doi:10.1016/j.cell.2004.09.030.
To be an evolutionist, you have to take the Crick brainwashing class. This involves repeating the following quote by Francis Crick over and over until it is engraved on the heart with an iron stylus: “Biologists must constantly keep in mind that what they see was not designed, but evolved.”