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A G-protein-coupled chemoattractant receptor recognizes lipopolysaccharide for bacterial phagocytosis

PLOS Biology (new articles) - пт, 2018-05-25 23:00

by Miao Pan, Matthew P. Neilson, Alexander M. Grunfeld, Phillip Cruz, Xi Wen, Robert H. Insall, Tian Jin

Phagocytes locate microorganisms via chemotaxis and then consume them using phagocytosis. Dictyostelium amoebas are stereotypical phagocytes that prey on diverse bacteria using both processes. However, as typical phagocytic receptors, such as complement receptors or Fcγ receptors, have not been found in Dictyostelium, it remains mysterious how these cells recognize bacteria. Here, we show that a single G-protein-coupled receptor (GPCR), folic acid receptor 1 (fAR1), simultaneously recognizes the chemoattractant folate and the phagocytic cue lipopolysaccharide (LPS), a major component of bacterial surfaces. Cells lacking fAR1 or its cognate G-proteins are defective in chemotaxis toward folate and phagocytosis of Klebsiella aerogenes. Computational simulations combined with experiments show that responses associated with chemotaxis can also promote engulfment of particles coated with chemoattractants. Finally, the extracellular Venus-Flytrap (VFT) domain of fAR1 acts as the binding site for both folate and LPS. Thus, fAR1 represents a new member of the pattern recognition receptors (PRRs) and mediates signaling from both bacterial surfaces and diffusible chemoattractants to reorganize actin for chemotaxis and phagocytosis.
Категории: Biology, Journals

Watch the weird new solutions to the baffling three-body problem

HIV and AIDS - пт, 2018-05-25 19:12
The three-body problem, which determines how objects orbit each other in space, is notoriously difficult to solve. Now there are 231 new valid orbits
Категории: Healthcare, Science and society

Pluto is not a planet – it’s a billion comets squished together

HIV and AIDS - пт, 2018-05-25 18:16
Pluto’s heart-shaped ice plain is full of nitrogen, which hints that the tiny world is made from a billion comets and could have a buried ocean
Категории: Healthcare, Science and society

Europe’s new data laws are a way to push back on Silicon Valley

HIV and AIDS - пт, 2018-05-25 18:00
The General Data Protection Regulation might not prove highly effective, but at least it tries to rein in the tech giants and put privacy above profit
Категории: Healthcare, Science and society

Minimally conscious people woken with brain zap by their family

HIV and AIDS - пт, 2018-05-25 14:00
Some people, who have been minimally conscious for years, could respond to questions from their loved ones for the first time after treatment with electricity
Категории: Healthcare, Science and society

Dentists can smell your fear – and it may put your teeth at risk

HIV and AIDS - пт, 2018-05-25 13:46
A study of sweaty T-shirts suggests dentists can smell when someone is anxious, and it makes them more likely to make mistakes and damage neighbouring teeth
Категории: Healthcare, Science and society

More lava flows reach the coast as volcano threatens Hawaii

HIV and AIDS - пт, 2018-05-25 12:54
Lava is entering the ocean off Hawaii from a third flow, marking the third week of a volcanic eruption that has opened up nearly two dozen vents,
Категории: Healthcare, Science and society

In big cities even the fish are always rushing around the place

HIV and AIDS - пт, 2018-05-25 11:00
Two common US fish have evolved different body shapes to help them survive in the fast-moving streams in built-up areas
Категории: Healthcare, Science and society

Unsolved mysteries: How does lipid peroxidation cause ferroptosis?

PLOS Biology (new articles) - чт, 2018-05-24 23:00

by Huizhong Feng, Brent R. Stockwell

Ferroptosis is a cell death process driven by damage to cell membranes and linked to numerous human diseases. Ferroptosis is caused by loss of activity of the key enzyme that is tasked with repairing oxidative damage to cell membranes—glutathione peroxidase 4 (GPX4). GPX4 normally removes the dangerous products of iron-dependent lipid peroxidation, protecting cell membranes from this type of damage; when GPX4 fails, ferroptosis ensues. Ferroptosis is distinct from apoptosis, necroptosis, necrosis, and other modes of cell death. Several key mysteries regarding how cells die during ferroptosis remain unsolved. First, the drivers of lipid peroxidation are not yet clear. Second, the subcellular location of lethal lipid peroxides remains an outstanding question. Finally, how exactly lipid peroxidation leads to cell death is an unsolved mystery. Answers to these questions will provide insights into the mechanisms of ferroptotic cell death and associated human diseases, as well as new therapeutic strategies for such diseases.
Категории: Biology, Journals

Asteroid that killed the dinosaurs caused massive global warming

HIV and AIDS - чт, 2018-05-24 21:00
The asteroid that struck Earth 66 million years ago caused dramatic climate change, which could mean we are underestimating how much the planet will warm in the coming centuries
Категории: Healthcare, Science and society

Uber self-driving car ‘saw woman but didn’t brake before crash’

HIV and AIDS - чт, 2018-05-24 19:10
An autonomous Uber car spotted Elaine Herzberg about six seconds before fatally hitting her but did not stop because the emergency brakes were disabled, US federal investigators said today
Категории: Healthcare, Science and society

Bulletproof batteries could make body armour for combat

HIV and AIDS - чт, 2018-05-24 18:53
The US Air Force is developing bulletproof batteries to replace traditional armour. They are loaded with silica nanoparticles that become rigid upon impact
Категории: Healthcare, Science and society

Fixing planet plastic: How we’ll really solve our waste problem

Genetically modified organisms (GMO) - чт, 2018-05-24 15:40
From bag bans to bacterial mulchers, many solutions are touted for the plastic waste crisis. Find out which work – and which don't – in our definitive guide
Категории: Science and society

Fixing planet plastic: How we’ll really solve our waste problem

Genetics - чт, 2018-05-24 15:40
From bag bans to bacterial mulchers, many solutions are touted for the plastic waste crisis. Find out which work – and which don't – in our definitive guide
Категории: Biology

‘Impossible’ EM drive doesn’t seem to work after all

HIV and AIDS - чт, 2018-05-24 15:35
A rocket engine propelled by electromagnetic waves grabbed headlines, but new tests find the EM drive may actually be driven by Earth’s magnetic field
Категории: Healthcare, Science and society

Nine curious colours that shaped the history of art

Genetically modified organisms (GMO) - чт, 2018-05-24 14:00
From purple sea snail milk to arsenic green and a yellow made from urine, we’ve gone to bizarre lengths in our millennia-long quest to create the most vibrant shades
Категории: Science and society

Nine curious colours that shaped the history of art

Genetics - чт, 2018-05-24 14:00
From purple sea snail milk to arsenic green and a yellow made from urine, we’ve gone to bizarre lengths in our millennia-long quest to create the most vibrant shades
Категории: Biology

Chimp evolution was shaped by sex with their bonobo relatives

Genetically modified organisms (GMO) - чт, 2018-05-24 13:45
Some chimpanzee populations gained useful DNA from interbreeding with bonobos, and one may even have become more gentle and “bonobo-like” in its brain structure and behaviour
Категории: Science and society

Chimp evolution was shaped by sex with their bonobo relatives

Genetics - чт, 2018-05-24 13:45
Some chimpanzee populations gained useful DNA from interbreeding with bonobos, and one may even have become more gentle and “bonobo-like” in its brain structure and behaviour
Категории: Biology

Chimp evolution was shaped by sex with their bonobo relatives

HIV and AIDS - чт, 2018-05-24 13:45
Some chimpanzee populations gained useful DNA from interbreeding with bonobos, and one may even have become more gentle and “bonobo-like” in its brain structure and behaviour
Категории: Healthcare, Science and society