Genome complexity: on-off gene switch found (Introduction)

by David Turell , Monday, December 21, 2015, 21:29 (3041 days ago) @ David Turell

It is important to control groups of genes at once, since more than one gene may be involves in certain processes:-http://phys.org/news/2015-12-genetic-theorists-reveal-mechanism-gene.html-"The regulatory switch the lab studied has three components: an NFkB protein transcription factor, IkB inhibitor proteins and the DNA that houses the genes.-"NFkB proteins are a family of dimeric (two-part) proteins that bridge extracellular signals and gene expression, alighting on DNA to activate the manufacture of specific proteins in response to outside stimuli. They organize many cellular functions, including the inflammatory response, immune response to infection and the programmed cell death that inhibits cancer.-***-"Because NFkB proteins can activate so many processes at once, timing is important, he said. "NFkB isn't just sending out one signal, turning on the manufacture of one new protein. It's running a broadcast network, turning on many genes, including IkB," Wolynes said. "The stripping mechanism means that instead of leaving all the genes turned on and letting each one figure out when to turn off, IkB strips the NFkB and makes sure they all get turned off. Transcription ends at that point."-"He said this shutdown appears to happen all at once. "If you have a process that turns on 100 different genes, you probably want them all also to turn off at the same time. You don't necessarily want five random genes taking their time, because that would lead to disorganized cell behavior."-"'In the classical picture of gene switches, we don't talk about time," Potoyan said. "We just understand that a gene turns on and off. But here, timing is critical because there are hundreds of genes being regulated. In molecular stripping, all the transcription sites become visible to IkB, which broadcasts the signal for every NFkB to unbind at once.-***-"'We believe this stripping process may be very general for master regulator genes," he said. "It's a system that violates that 40- to 50-year-old paradigm of how a gene switch works. That's one of the reasons we think this study is important.'" -Comment: Genome complexity increases. My standard observation: How did evolution found this complex enzyme with such exact function? Design?