A new class of hybrid secretion system is employed in Pseudomonas amyloid biogenesis

Gram-negative bacteria possess specialised biogenesis machineries that facilitate the export of amyloid subunits for construction of a biofilm matrix. The secretion of bacterial functional amyloid requires a bespoke outer-membrane protein channel through which unfolded amyloid substrates are translocated. Here, we combine X-ray crystallography, native mass spectrometry, single-channel electrical recording, molecular simulations and circular dichroism measurements to provide high-resolution structural insight into the functional amyloid transporter from Pseudomonas, FapF. FapF forms a trimer of gated β-barrel channels in which opening is regulated by a helical plug connected to an extended coil-coiled platform spanning the bacterial periplasm. Although FapF represents a unique type of secretion system, it shares mechanistic features with a diverse range of peptide translocation systems. Our findings highlight alternative strategies for handling and export of amyloid protein sequences

Inside and out: the activities of senescence in cancer.

The core aspect of the senescent phenotype is a stable state of cell cycle arrest. However, this is a disguise that conceals a highly active metabolic cell state with diverse functionality. Both the cell-autonomous and the non-cell-autonomous activities of senescent cells create spatiotemporally dynamic and context-dependent tissue reactions. For example, the senescence-associated secretory phenotype (SASP) provokes not only tumour-suppressive but also tumour-promoting responses. Senescence is now increasingly considered to be an integrated and widespread component that is potentially important for tumour development, tumour suppression and the response to therapy.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/nrc377

Senescent cells as a source of inflammatory factors for tumor progression

Cellular senescence, which is associated with aging, is a process by which cells enter a state of permanent cell cycle arrest, therefore constituting a potent tumor suppressive mechanism. Recent studies show that, despite the beneficial effects of cellular senescence, senescent cells can also exert harmful effects on the tissue microenvironment. The most significant of these effects is the acquisition of a senescent-associated secretory phenotype (SASP), which entails a striking increase in the secretion of pro-inflammatory cytokines. Here, we summarize our knowledge of the SASP and the impact it has on tissue microenvironments and ability to stimulate tumor progression

The disposition of theophylline in patients with lung and breast cancer.

The influence of extrahepatic neoplastic disease on the biotransformation of theophylline was assessed by comparing the pharmacokinetic and metabolic profile of the drug in six patients with advanced breast or bronchial carcinoma, without detectable liver metastases, and in six appropriately matched control subjects. Each subject was given a single dose of theophylline (5 mg/kg) in oral solution; blood and urinary samples were collected for up to 24 h after dosing. Theophylline was absorbed rapidly in all subjects and within 2 h reached comparable peak concentrations in both groups (cancer patients: 57.8 +/- 14.4 mumol/l; controls; 65.0 +/- 10.6 mumol/l; N.S., means +/- s.d.). No significant differences were observed between cancer patients and controls for theophylline apparent volume of distribution (0.44 +/- 0.07 vs 0.40 +/- 0.06 l/kg), total body clearance (40.8 +/- 12.8 vs 34.8 +/- 13.0 ml kg-1 h-1) and elimination half-life (8.0 +/- 1.6 vs 8.5 +/- 1.8 h). The excretion of the major metabolites 3-methyl-xanthine and 1,3-dimethyl-uric acid was also very similar in the two groups. These data do not provide any evidence for an altered rate or pattern of theophylline biotransformation in patients with advanced extrahepatic neoplastic disease

Adapting the semi-explicit assembly solvation model for estimating water-cyclohexane partitioning with the SAMPL5 molecules

We describe here some tests we made in the SAMPL5 communal event of `Semi-Explicit Assembly' (SEA), a recent method for computing solvation free energies. We combined the prospective tests of SAMPL5 with followup retrospective calculations, to improve two technical aspects of the field variant of SEA. First, SEA uses an approximate analytical surface around the solute on which a water potential is computed. We have improved and simplified the mathematical model of that surface. Second, some of the solutes in SAMPL5 were large enough to need a way to treat solvating waters interacting with `buried atoms', i.e. interior atoms of the solute. We improved SEA with a buried-atom correction. We also compare SEA to Thermodynamic Integration molecular dynamics simulations, so that we can sort out force field errors