Genome complexity: enzyme repairs broken DNA 2 (Introduction)

by David Turell , Friday, September 09, 2016, 22:55 (2996 days ago) @ David Turell

Another part of the DNA repair process is found using a large enzyme:-http://phys.org/news/2016-09-dna.html-"To find out what activates SIRT6, the researchers alternately applied chemical inhibitors to human skin cells to determine which proteins were essential in getting the gene to repair the broken DNA strands. They discovered that one protein was involved in activating the gene in response to oxidative stress—c-Jun N-terminal kinase, which goes by the simpler term JNK. When JNK was inhibited, SIRT6 was not activated and the broken strands of DNA were not repaired efficiently. -"To communicate stress signals within cells, JNKs add phosphate groups to proteins, and the Rochester study found the amino acid residue on SIRT6 that is modified by JNK. Once modified, SIRT6 can attract the enzyme PARP1 (Poly [ADP-ribose] polymerase 1) to the damaged site, where the enzyme undertakes a chemical process to repair the DNA. In effect, the activated gene serves as a first responder, recruiting DNA repair enzymes to the accident site and getting them to work.-"The study is the latest work by Gorbunova and Seluanov to shed light on the molecular mechanisms that drive the aging process. Their previous work involved understanding the prominence of an inferior DNA repair process later in life, as well as how errant DNA fragments—called jumping genes—are typically kept inactive."-Comment: Note these are automatic molecular reactions. Once again Note the use of giant enzymes which raise the issue of how did evolution find this type of molecule. I'm still suggesting saltation.