Skip to main content
Premium Trial:

Request an Annual Quote

This Week in PNAS: Jun 9, 2009

Scientists at the the University of Texas Southwestern Medical Center and Chinese Academy of Sciences in Beijing collaborated on a study published this week in the early online edition of PNAS that looked at phosphorylation events of the Neurospora core circadian protein FRQ. Using mass spec, they identified 43 FRQ phosphorylation sites in vivo and another 33 by in vitro kinase assays. "Whole-cell metabolic isotope labeling and quantitative MS analyses suggest that circadian oscillation of the FRQ phosphorylation profile is primarily due to progressive phosphorylation at the majority of these newly discovered phosphorylation sites," they write in the abstract, suggesting that FRQ stability and thus, circadian rhythm, is mediated by phosphorylation.

Work by Yann Gambina and Alexander Schug at Scripps and UCSD, respectively, used single-molecule fluorescence resonance energy transfer (smFRET) measurements to see that two "symmetrically opposed conformations" for a mutant of the Rop-homodimer (Repressor of Primer) exist together. Mild denaturing conditions can affect the sensitive balance between the conformations, they found, and that the proteins can switch between conformations.

More proteomics work on structure/function relationship revealed that the physicochemical properties of proteins' amino acid sequences can affect the way they associate and interact. Upon analyzing all the protein-protein complexes in the Protein Data Bank, scientists in the UK found that interface regions are more likely to aggregate than other surface regions. This suggests that interactions that promote function, like hydrophobic and electrostatic forces, can also cause abnormal associations. Further work showed that disulfide bonds and salt bridges, however, can act as stabilizing forces.

Senior author Gareth Bond at Oxford's Ludwig Institute for Cancer Research led work that studied the effect of mutations in the MDM4 gene, a homolog of the mouse double minute 2 (MDM2) oncogene, which binds to and inhibits p53. Looking at the haplotype structure of MDM4 in multiple populations and association studies in five different patient populations, they found that SNPs in this region lend an increased risk for, or early onset of, human breast and ovarian cancers in Ashkenazi Jewish and European cohorts, respectively, they say.

The Scan

Two J&J Doses

Johnson & Johnson says two doses of its SARS-CoV-2 vaccine provides increased protection against symptomatic COVID-19, CNN reports.

Pfizer-BioNTech Vaccine Response in Kids

The Pfizer-BioNTech SARS-CoV-2 vaccine in a lower-dose format appears to generate an immune response among children, according to the Washington Post.

Chicken Changes to Prevent Disease

The Guardian writes that researchers are looking at gene editing chickens to help prevent future pandemics.

PNAS Papers on Siberian Dog Ancestry, Insect Reproduction, Hippocampal Neurogenesis

In PNAS this week: ancestry and admixture among Siberian dogs, hormone role in fruit fly reproduction, and more.