Researchers explain how animals sense potentially harmful acids

Proposed model for how acetic acid might activate the ion channel TRPA1. A new study in the Journal of General Physiology identifies TRPA1 as the sensor in animals responsible for identifying weak acids, an important class of potentially harmful chemicals. Credit: Wang, Y.Y., et al. 2011. J. Gen. Physiol. doi:10.1085/jgp.201110615.

All animals face the challenge of deciding which chemicals in the environment are useful and which are harmful. A new study greatly improves our understanding of how animals sense an important class of potentially harmful chemicals: weak acids. The study appears online on May 16 in the Journal of General Physiology.

Weak acids like acetic acid (vinegar) and propionic acid (present in fermented foods like Swiss cheese) are shunned by many animals, and with good reason. Many in the environment can have widespread detrimental effects. Humans ingest these substances despite the fact that they actually elicit "irritating" sensations, a that may have been vital for our ancestors' survival.

So what are the molecular sensors and mechanisms involved when animals detect these substances? Although researchers have identified sensors for many , the mechanisms involved in the detection of weak acids have been a mystery. Now, University of Southern California researcher Emily Liman and colleagues identify the sensor as none other than the ion channel TRPA1. The authors show that TRPA1 responds to weak acids when they acidify the cytoplasm within the cell. Such cytoplasmic acidification can have very —even triggering cell death—which explains why this process raises such alarm bells in animals.

Researchers have been surprised in recent years to discover how many different types of noxious stimuli can be sensed by TRPA1, explains Brandeis University's Paul Garrity in a Commentary accompanying the study. With this latest research, weak acids can be added to that growing list.

More information:
Garrity, P.A. 2011. J. Gen. Physiol. doi:10.1085/jgp.201110657
Wang, Y.Y., et al. 2011. J. Gen. Physiol. doi:10.1085/jgp.201110615

Related Stories

Scientists sniff out the evolution of chemical nociception

Mar 17, 2010

Whenever you choke on acrid cigarette smoke, feel like you're burning up from a mouthful of wasabi-laced sushi, or cry while cutting raw onions and garlic, your response is being triggered by a primordial chemical sensor ...

Recommended for you

Growing a blood vessel in a week

1 hour ago

The technology for creating new tissues from stem cells has taken a giant leap forward. Three tablespoons of blood are all that is needed to grow a brand new blood vessel in just seven days. This is shown ...

Testing time for stem cells

4 hours ago

DefiniGEN is one of the first commercial opportunities to arise from Cambridge's expertise in stem cell research. Here, we look at some of the fundamental research that enables it to supply liver and pancreatic ...

Team finds key signaling pathway in cause of preeclampsia

23 hours ago

A team of researchers led by a Wayne State University School of Medicine associate professor of obstetrics and gynecology has published findings that provide novel insight into the cause of preeclampsia, the leading cause ...

Rapid test to diagnose severe sepsis

Oct 23, 2014

A new test, developed by University of British Columbia researchers, could help physicians predict within an hour if a patient will develop severe sepsis so they can begin treatment immediately.

User comments