15 December 2009
Vol 2, Issue 101
  • Contents

    • Research Articles

    • Perspectives

    • Podcast

    • Editors' Choice

      • Evolution of Metabolic Diseases

        Integration of ancestral immune responses with mobilization of energy stores provides clues to understanding metabolic diseases in humans.

      • It’s All Relative

        As long as the fold change in the signal remains the same, the output of the signaling network is robust to changes in the absolute amount of the signal.

      • Exciting Structures

        The solution to the structure of the AMPA receptor reveals clues about the general mechanisms of action of ionotropic glutamate receptors.

      • Dissecting Ephrin-Receptor Interaction

        A proteomic strategy elucidates signaling networks between cells communicating through ephrin proteins and their receptors.

      • Norbin Knockout

        The protein Norbin regulates the accumulation of a neurotransmitter receptor in mouse brain cell membranes.

      • An Innervative Small RNA

        A small noncoding RNA promotes nerve-muscle interactions in response to motor neuron injury and slows disease progression.

About The Cover

Cover image expansion

Online Cover This week's issue features a Research Article that defines a role for the catalytic activity of the Vav1 guanine nucleotide exchange factor (GEF) in T cell biology. The image shows a complex between the catalytic core of Vav1 in gray and its substrate, the Rac1 GTPase, in gold. The locations of Leu334 and Lys335 in the Dbl homology (DH) domain of Vav1 are indicated in red. These two amino acid residues make key contacts with Rac1 and are essential for the exchange reaction. Experiments with mice that have a knock-in mutation in these residues showed that Vav1 has both GEF-dependent and GEF-independent activities that are necessary for T cell development and activation. [Image: Steve Smerdon, MRC National Institute for Medical Research, London, UK]