24 June 2008
Vol 1, Issue 25
  • Contents

    • Perspectives

    • Review

    • Editors' Choice

      • Counting Phosphates

        The DNA-damage-response kinase Dun1 must bind, through its FHA domain, to not one, but two phosphothreonine residues to be activated by the kinase Rad53.

      • Regulating the Regulators

        Mitosis begins in mammalian cells when a protein accumulates between cell divisions and interacts with a second protein to initiate a cascade of kinase activation.

      • β3 Integrin as a Coreceptor for TLR2

        Vitronectin appears to bind bacterial lipopeptides to present these to a complex of integrins with β3 subunits and Toll-like receptor 2.

      • Sometimes Less Is More

        T cell activation induces the production of mRNAs with shorter 3′UTRs and fewer microRNA target sites.

      • Plant Hair Signals

        Movement between cells appears to drive the accumulation of the protein TTG1 into the cells that form trichomes, while depleting neighboring cells.

      • Glial Cell Tuning

        Astrocytes in the visual cortex respond to visual stimuli, showing receptive field properties (response kinetics, orientation, and localization) similar to those of neurons.

About The Cover

Cover image expansion

COVER This week's issue features a Review that discusses how heterotrimeric guanosine triphosphate (GTP)-binding proteins (G proteins) may function as activated heterotrimers. This is in addition to the well-characterized abilities of dissociated α and βγ subunits to function independently. The image shows the structure of a heterotrimeric G protein, which consists of α (blue), β (purple), and γ (green) subunits and is based on PDB structure 1GP2. [Image: Chris Bickel, AAAS]