Skip to main content
eScholarship
Open Access Publications from the University of California

Scholarly Works (4 results)

  • Article
  • Peer Reviewed
UC San Diego Previously Published Works (2004)

The Listeria monocytogenes protein InlB promotes intracellular invasion by activating the receptor tyrosine kinase Met. Earlier studies have indicated that the LRR fragment of InlB is sufficient for Met activation, but we show that this is not the case unless the LRR fragment is artificially dimerized through a disulphide bond. In contrast, activation of Met proceeds through monomers of intact InlB and, at physiologically relevant concentrations, requires coordinated action in cis of both InlB N-terminal LRR region and C-terminal GW domains. The GW domains are shown to be crucial for potentiating Met activation and inducing intracellular invasion, with these effects depending on association between GW domains and glycosaminoglycans. Glycosaminoglycans do not alter the monomeric state of InlB, and are likely to enhance Met activation through a receptor-mediated mode, as opposed to the ligand-mediated mode observed for the LRR fragment. Surprisingly, we find that gC1q-R, a host protein implicated in InlB-mediated invasion, specifically antagonizes rather than enhances InlB signalling, and that interaction between InlB and gC1q-R is unnecessary for bacterial invasion. Lastly, we demonstrate that HGF, the endogenous ligand of Met, substitutes for InlB in promoting intracellular invasion, suggesting that no special properties are required of InlB in invasion besides its hormone-like mimicry of HGF.

    Cover page: GW domains of the Listeria monocytogenes invasion protein InlB are required for potentiation of Met activation
    • Article
    • Peer Reviewed
    UC San Diego Previously Published Works (2019)
    An overview from the past and an outlook for the future of fundamental laser-plasma interactions research enabled by emerging laser systems.
      Cover page: Laser-Plasma Interactions Enabled by Emerging Technologies
      • Article
      • Peer Reviewed
      UC Berkeley Previously Published Works (2024)
      Indirect Drive Inertial Confinement Fusion Experiments on the National Ignition Facility (NIF) have achieved a burning plasma state with neutron yields exceeding 170 kJ, roughly 3 times the prior record and a necessary stage for igniting plasmas. The results are achieved despite multiple sources of degradations that lead to high variability in performance. Results shown here, for the first time, include an empirical correction factor for mode-2 asymmetry in the burning plasma regime in addition to previously determined corrections for radiative mix and mode-1. Analysis shows that including these three corrections alone accounts for the measured fusion performance variability in the two highest performing experimental campaigns on the NIF to within error. Here we quantify the performance sensitivity to mode-2 symmetry in the burning plasma regime and apply the results, in the form of an empirical correction to a 1D performance model. Furthermore, we find the sensitivity to mode-2 determined through a series of integrated 2D radiation hydrodynamic simulations to be consistent with the experimentally determined sensitivity only when including alpha-heating.
        Cover page: The impact of low-mode symmetry on inertial fusion energy output in the burning plasma state.
        • Article
        • Peer Reviewed
        UC Irvine Previously Published Works (2022)
        For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.
          Cover page: Lawson Criterion for Ignition Exceeded in an Inertial Fusion ExperimentCreative Commons 'BY-NC' version 4.0 license
          Top