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This Week in PNAS: Nov 28, 2012

Unintentional physical interactions between proteins crowded together in the same cell can influence proteome evolution and function, according to a study in the early, online edition of the Proceedings of the National Academy of Sciences. An international team led by investigators in the UK looked at relationships between the three-dimensional structure of proteins and their abundance. Based on data for hundreds of Escherichia coli, budding yeast, and human proteins, the researchers saw that proteins more prone to non-specific interactions also tend to be less plentiful. On the other hand, more bountiful proteins usually had fewer of the relatively well-conserved "sticky" surfaces. Such effects were more pronounced for E. coli and yeast proteins than for human proteins, study authors say, hinting that "promiscuous protein-protein interactions may be freer to accumulate in the human lineage."

Researchers from Germany, New Zealand, and Ireland explore historical lateral gene transfer events between microbes — and their influence on the evolution of halophilic archaebacteria, or "haloarchaea," microbes adapted to life in very salt-rich environments. Using data from 10 haloarchaeal genomes and more than 1,100 archaebacteria or eubacteria reference genomes, that team determined that the evolution of haloarchaea from methanogens likely relied on the acquisition of more than 1,000 genes from eubacteria. A shared haloarchaeal ancestor seems to have nabbed the genes in a single event, researchers say, leading to a haloarchaeal lineage capable of respiring oxygen rather than subsisting on hydrogen in oxygen-depleted conditions, as is the case for methanogens. "The origin of Haloarchaea was … an evolutionary leap," researchers write, "that transformed a methanogenic host into an oxygen-respiring heterotroph — the founder haloarchaeon."

Finally, National Institutes of Health comparative ethnology researcher Stephen Suomi and his colleagues report on variable transcriptional regulation in developing immune cells that are related to early life exposures in rhesus macaque monkeys. The researchers measured gene expression patterns genome-wide in basal leukocyte white blood cells from four four-month-old macaques that had been raised by an inanimate surrogate or peer rather than their mothers — an adverse social condition previously linked to certain health risks in adulthood. Compared to with age-matched macaques raised by their own mothers, the socially stressed monkeys had distinct expression profiles at almost 250 genes. For instance, the team reports, the stressed macaques had higher-than-usual levels of several inflammation and immunity related genes, along with decreased expression of genes contributing to antimicrobial immunity and pathogen response.

The Scan

Genes Linked to White-Tailed Jackrabbits' Winter Coat Color Change

Climate change, the researchers noted in Science, may lead to camouflage mismatch and increase predation of white-tailed jackrabbits.

Adenine Base Editor Targets SCID Mutation in New Study

Researchers from the University of California, Los Angeles, report in Cell that adenine base editing was able to produce functional T lymphocytes in a model of severe combined immune deficiency.

Researchers Find Gene Affecting Alkaline Sensitivity in Plants

Researchers from the Chinese Academy of Science have found a locus affecting alkaline-salinity sensitivity, which could aid in efforts to improve crop productivity, as they report in Science.

International Team Proposes Checklist for Returning Genomic Research Results

Researchers in the European Journal of Human Genetics present a checklist to guide the return of genomic research results to study participants.