PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Negative feedback makes cells 'sensitive'

2014-01-08
(Press-News.org) Contact information: Joanne Fryer
joanne.fryer@bristol.ac.uk
44-011-733-17276
University of Bristol
Negative feedback makes cells 'sensitive' New research has shown that negative feedback loops in cell signalling systems can be essential for a cell's ability to perceive the strength of a growth stimulus. Cells lacking the feedback loop became insensitive to the level of the stimulus in a manner similar to a cancerous cell displaying unrestrained growth.

Living cells need to sense changes in their environment reliably in order to make appropriate decisions. The biomolecular machinery they use to perform these tasks is surprisingly noisy. Combining automated cell imaging and mathematical analysis, the team from the University of Bristol explored what happens when the signalling system in the cell has a background level of activation even when no stimulus is present, similar to a light bulb that glows even when its switch is off.

The collaborative study, carried out by the groups of Dr Clive Bowsher in the School of Mathematics and Professor Craig McArdle in the School of Clinical Sciences, is published online this week in PNAS.

Using information theory and statistics to analyse the data from images of hundreds of thousands of individual cells, the team showed that mutant cells lacking the negative feedback loop could not detect the level of growth factor.

"Breaking the feedback loop resulted in a dramatic and surprising reduction in the information the cell has about its environment," said Dr Margaritis Voliotis in the School of Mathematics and MRC Fellow on the team.

Dr Bowsher, who led the study, explained: "We realised that basal activity can be high enough in kinase signalling to create a dichotomy: the networks with negative feedback continue to function as effective sensors while the mutant networks do not."

Basal activity of signalling pathways is often raised in disease, and the interplay between basal activity and negative feedback is known to be important in cancers like melanoma. The research is expected to improve understanding at the molecular level of how decisions are made by healthy cells and of how signalling goes wrong in diseased cells.

### Paper: Information transfer by leaky, heterogeneous, protein kinase signaling systems, by Margaritis Voliotis, Rebecca M. Perrett, Chris McWilliams, Craig A. McArdle, and Clive G. Bowsher, PNAS, published online 6 January 2014.


ELSE PRESS RELEASES FROM THIS DATE:

Heart attacks hit poor the hardest

2014-01-08
Heart attacks hit poor the hardest Tel Aviv University researchers show that socioeconomic status is predictor of higher risk of disease and death after an attack As people get older, their bodies wear down and become less resilient. In old age, it's ...

The ironic (and surprising) effects of weight stigma

2014-01-08
The ironic (and surprising) effects of weight stigma UCSB psychology professor finds that messages designed to encourage weight loss may actually have the opposite effect (Santa Barbara, Calif.) — If you're one of the millions of people who ...

Penn biologists establish new method for studying RNA's regulatory 'footprint'

2014-01-08
Penn biologists establish new method for studying RNA's regulatory 'footprint' Increasingly, biologists have come to realize that RNA is not merely a transitional state between DNA and proteins but plays a major role in determining whether and how genes ...

Scripps Florida scientists identify possible key to drug resistance in Crohn's disease

2014-01-08
Scripps Florida scientists identify possible key to drug resistance in Crohn's disease JUPITER, FL, January 7, 2014 – Two-thirds to three-quarters of the estimated 700,000 Americans living with Crohn's disease, an autoimmune condition that can disrupt the entire ...

Massive exoplanets may be more Earth-like than thought

2014-01-08
Massive exoplanets may be more Earth-like than thought 'Super-Earths' likely to have both oceans and continents Massive terrestrial planets, called "super-Earths," are known to be common in our galaxy, the Milky Way. Now a Northwestern University astrophysicist ...

Many small exoplanets found to be covered in gas

2014-01-08
Many small exoplanets found to be covered in gas New measurements of mass expand knowledge of exoplanets' compositions During its four-year mission, NASA's Kepler space telescope discovered thousands of "planetary candidates" in our Milky Way galaxy -- the vast ...

Sugar-sweetened beverage tax could reduce obesity and type 2 diabetes in India

2014-01-08
Sugar-sweetened beverage tax could reduce obesity and type 2 diabetes in India A sugar-sweetened beverage (SSB) tax could help mitigate the rise in obesity and type 2 diabetes rates in India among both urban and rural populations, according to a study published this week ...

Link found between intimate partner violence and termination of pregnancy

2014-01-08
Link found between intimate partner violence and termination of pregnancy Intimate partner violence in women (sometimes referred to as domestic violence) is linked to termination of pregnancy, according to a study by UK researchers published in this week's PLOS Medicine. ...

50 years of tobacco control significantly extended lives of 8 million Americans

2014-01-08
50 years of tobacco control significantly extended lives of 8 million Americans Former smoker John Hilburn says a cigarette warning label and costs prompted him to kick the habit 30 years ago WASHINGTON — The Surgeon General's report of 1964 which outlined, for the ...

Despite declines in smoking rates, number of smokers and cigarettes rises

2014-01-08
Despite declines in smoking rates, number of smokers and cigarettes rises Population growth since 1980 drives increases in countries including China and Russia while Canada, Mexico, and the United States see strong declines SEATTLE — Globally, smoking ...

LAST 30 PRESS RELEASES:

Pink skies

Monkeys are world’s best yodellers - new research

Key differences between visual- and memory-led Alzheimer’s discovered

% weight loss targets in obesity management – is this the wrong objective?

An app can change how you see yourself at work

NYC speed cameras take six months to change driver behavior, effects vary by neighborhood, new study reveals

New research shows that propaganda is on the rise in China

Even the richest Americans face shorter lifespans than their European counterparts, study finds

Novel genes linked to rare childhood diarrhea

New computer model reveals how Bronze Age Scandinavians could have crossed the sea

Novel point-of-care technology delivers accurate HIV results in minutes

Researchers reveal key brain differences to explain why Ritalin helps improve focus in some more than others

Study finds nearly five-fold increase in hospitalizations for common cause of stroke

Study reveals how alcohol abuse damages cognition

Medicinal cannabis is linked to long-term benefits in health-related quality of life

Microplastics detected in cat placentas and fetuses during early pregnancy

Ancient amphibians as big as alligators died in mass mortality event in Triassic Wyoming

Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly

Alcohol makes male flies sexy

TB patients globally often incur "catastrophic costs" of up to $11,329 USD, despite many countries offering free treatment, with predominant drivers of cost being hospitalization and loss of income

Study links teen girls’ screen time to sleep disruptions and depression

Scientists unveil starfish-inspired wearable tech for heart monitoring

Footprints reveal prehistoric Scottish lagoons were stomping grounds for giant Jurassic dinosaurs

AI effectively predicts dementia risk in American Indian/Alaska Native elders

First guideline on newborn screening for cystic fibrosis calls for changes in practice to improve outcomes

Existing international law can help secure peace and security in outer space, study shows

Pinning down the process of West Nile virus transmission

UTA-backed research tackles health challenges across ages

In pancreatic cancer, a race against time

Targeting FGFR2 may prevent or delay some KRAS-mutated pancreatic cancers

[Press-News.org] Negative feedback makes cells 'sensitive'