A paper in the early online edition of Science this weeks points to findings that suggest that lack of sleep leads to buildup of amyloid-beta protein in the brain, a hallmark of Alzheimer's disease. Monitoring the levels of this protein using in vivo microdialysis in mice, researchers led by Washington University scientists revealed that "preventing the mice from sleeping caused a 25 [percent] increase in amyloid beta levels," says a story in the Guardian. They also found a link between increased levels of orexin, a protein involved in regulating the sleep cycle, and higher amounts of amyloid beta.
Jocelyn Kaiser reports on a National Academies panel calling for a "multidisciplinary initiative to address four major societal problems involving food, energy, the environment, and health." Titled, A New Biology for the 21st Century, the report from the 16-member panel addresses areas such as biofuel production and personalized medicine, which need multidisciplinary research efforts – they "cannot be solved in isolation," says Keith Yamamoto, a panelist and molecular biologist at the University of California, San Francisco.
Two papers this week take a look at the evolution of protein phosphorylation. In one, scientists used quantitative mass spec on an engineered strain of Saccharomyces cerevisiae to find the range of phosphorylation sites for cyclin-dependent kinase Cdk1. They found 547 phosphorylation sites on 308 Cdk1 substrates, with further comparative analysis showing that "the position of most phosphorylation sites is not conserved in evolution; instead, clusters of sites shift position in rapidly evolving disordered regions." In the second study, through comparing the number of tyrosine residues in human versus yeast proteins, researchers found that tyrosine residues have been lost over the course of evolution. A perspective sheds more light.
Looking at mustard plants, the University of Strasbourg's Danièle Werck-Reichhart was first author on work that found that evolution in the cytochrome P450 enzyme family came from retroposition, duplication, and mutation events. The new enzymes helped create a novel metabolic pathway that makes pollen. "This example shows how positive Darwinian selection can favor structured clusters of nonsynonymous substitutions that are needed for the transition of enzymes to new functions," says the abstract.