Mechanisms of active solubilization of stable protein aggregates by molecular chaperones

Protein destabilization by mutations or external stresses may lead to misfolding and aggregation in the cell. Often, damage is not limited to a simple loss of function, but the hydrophobic exposure of aggregate surfaces may impair membrane functions and promote the aggregation of other proteins. Such a "proteinacious infectious" behavior is not limited to prion diseases. It is associated to most protein-misfolding neurodegenerative diseases and to aging in general. With the molecular chaperones and proteases, cells have evolved powerful tools that can specifically recognize and act upon misfolded and aggregated proteins. Whereas some chaperones passively prevent aggregate formation and propagation, others actively unfold and solubilize stable aggregates. In particular, ATPase chaperones and proteases serve as an intracellular defense network that can specifically identify and actively remove by refolding or degradation potentially infectious cytotoxic aggregates. Here we discuss two types of molecular mechanisms by which ATPase chaperones may actively solubilize stable aggregates: (1) unfolding by power strokes, using the Hsp100 ring chaperones, and (2) unfolding by random movements of individual Hsp70 molecules. In bacteria, fungi, and plants, the two mechanisms are key for reducing protein damages from abiotic stresses. In animals devoid of Hsp100, Hsp70 appears as the core element of the chaperone network, preventing the formation and actively removing disease-causing protein aggregates

Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13 TeV with the ATLAS Detector

International audienceThis Letter reports the observation of $WWW$ production and a measurement of its cross section using 139 fb$^{-1}$ of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from $WWW$ production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive $WWW$ production cross section is measured to be $820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)}$ fb, approximately 2.6 standard deviations from the predicted cross section of $511 \pm 18$ fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy

Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13 TeV with the ATLAS Detector

International audienceThis Letter reports the observation of $WWW$ production and a measurement of its cross section using 139 fb$^{-1}$ of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from $WWW$ production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive $WWW$ production cross section is measured to be $820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)}$ fb, approximately 2.6 standard deviations from the predicted cross section of $511 \pm 18$ fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy

Observation of WWWWWW Production in pppp Collisions at s\sqrt s =13 TeV with the ATLAS Detector

International audienceThis Letter reports the observation of $WWW$ production and a measurement of its cross section using 139 fb$^{-1}$ of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from $WWW$ production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive $WWW$ production cross section is measured to be $820 \pm 100\,\text{(stat)} \pm 80\,\text{(syst)}$ fb, approximately 2.6 standard deviations from the predicted cross section of $511 \pm 18$ fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy