In this week’s Science, researchers at the Autonomous National University of Mexico created modified Bt toxins that could kill Bt-resistant insects. Their work, which involved deleting one alpha-helix from Bt toxin Cry1Ab, showed that cadherin deletion mutations in pests confers resistance to Bt toxin, and that engineered Bt toxins can overcome this resistance.
At the Curie Institute, scientists have found that a region about 200 kilobases upstream of the X-inactivation center (Xic) brings the two Xics together before X inactivation. Effective dosage compensation in mammals consists of silencing of one of the two X chromosomes in females and is controlled by the Xic. The pairing might activate Xist, a noncoding RNA that coats the inactive X chromosome.
Genentech researchers used a siRNA screen to locate deubiquitinating enzymes that influenced expression of the interferon I (IFN-I) gene. They found DUBA is one and showed that depleting this enzyme increased expression of IFN-I and enhancing it inhibited expression. They also found TRAF3, an ubiquitin ligase which is required for induced expression of IFN-I, as a potential target of DUBA.
A retrospective on Arthur Kornberg, who passed away on October 26, remembers him as one of the greatest biochemists of the 20th century, whose work discovering DNA polymerase won him the Nobel Prize in Physiology and Medicine in 1959.