Genome complexity: Plant DNA discoveries (Introduction)

by David Turell , Thursday, January 01, 2015, 16:08 (3395 days ago) @ David Turell

More on plant research helping to explain how RNA helps to mediate gene functions, so that 20,000 genes can make a human being:-http://phys.org/news/2014-12-scientists-patterns-rna-nuclei.html-"Focusing on sections of RNA that bind to RBPs, [RNA binding proteins] the team found that these sequences have been conserved over evolutionary time and are likely playing an important function in gene regulatory mechanisms.-"The scientists also found a strong inverse relationship between patterns of RBP binding and secondary structure.-"When structure is low, proteins tend to bind those regions and when structure is high, RBPs tend to not bind those regions," Gregory said. "Time and time again, we've seen that the structural context, and not just the RNA sequence, is a selective force in RBP binding."-"Another significant finding was unique patterns of RBP binding and structure present around the start codon of each messenger RNA transcript, which is where a cell's protein-making machinery begins the process of making RNA in proteins.-"This is suggesting that there is a regulatory event happening here even before the RNA comes out of the nucleus and engages with the translation machinery," Gosai said. "It's an exciting place for future studies to start with and figure out what regulation events are happening in the nucleus."-"Two key forms of transcript regulation are alternative splicing, in which pieces of RNA undergo a cut-and-paste process to generate new sequences that can code for various proteins, and alternative polyadenylation, which alters where a transcript ends and an adenine "tail" is added, a process that can enhance either stabilization or degradation of the RNA molecule.-"In their analysis, the Penn biologists found that RBP-binding sites and certain patterns of secondary structure were much more common at sites where alternative splicing and alternative polyadenylation occur.-"In humans, almost 95 percent of genes are alternatively spliced, and the number is at least 60 percent in plants," said Foley. "To see high levels of RBP binding and an interplay with secondary structure at sites of alternative splicing and polyadenylation in plants is good indication of where and how regulation is occurring to produce different proteins from one RNA sequence."- Read more at: http://phys.org/news/2014-12-scientists-patterns-rna-nuclei.html#jCp-
 Read more at: http://phys.org/news/2014-12-scientists-patterns-rna-nuclei.html#jCp