Biophysics meeting roundup

Researchers attending the 55th meeting of the Biophysical Society in Baltimore, Maryland, presented their latest findings, from the promise of a newly discovered spider toxin in studying pain to advances in molecular imaging techniques. Below are some highlights from the meeting.Switching on neural receptorsAttaching light-sensing molecules to receptors inside neurons, researchers are able to turn the receptors on and off with millisecond accuracy simply by flashing some light. This makes it possible to "probe specific receptors in living organisms," said Joshua Levitz, a graduate student at the University of California, Berkeley, who helped develop the technique. Applying the method to G-protein-coupled receptors, Levitz can study the hippocampus, where memories are formed, stored and maintained. The light-sensitive G-protein-coupled receptors may one day prove useful in the clinic by, for example, manipulating the retina's G-protein-coupled receptors, which are critical for vision.Toxic tool for studying pain

Image: Wikimedia commons, Fir0002

A newly discovered spider toxin that interferes with certain types of calcium channels involved in pain may provide a new tool for studying the channels' activity and function. The channels blocked by the toxin also play roles in other conditions, such as congestive heart failure, hypertension, and epilepsy. "If we can develop a calcium-channel blocker based on this toxin, we could have a new way to identify how these channels work and develop drugs for treating pain and disease," said lead researcher Xiao Zhang, a postdoc at the Del Webb Center for Neuroscience in La Jolla, Calif. Delving into deafnessTwo groups presented their findings about the genetic and molecular details of deafness. One group identified how a single amino acid change in an inner ear motor protein called myo1c can result in hearing loss. Like other mutations in myo1c, the mutation -- called R156W -- interferes with the protein's interaction with actin filaments, reducing its sensitivity to the mechanical forces triggered by sounds entering the ear.Another group announced the discovery of a new type of genetic deafness. Two families in Pakistan with mutations in the CACNA1D gene, which encodes a protein component of L-type calcium channels, have irregular heartbeats and are deaf, much like knockout mouse models of the gene. The mutation, which adds an additional amino acid in the middle of the 2,000-amino acid protein, appears to affect the protein's function as the hinge that opens the channel.Molecular imaging advancesImaging complex cellular process has been a long-standing challenge for scientists studying basic cell biology. Now, a novel 3D cell imaging method presents a possible solution, combining two existing technologies -- multifocal plane microscopy and nanodot labeling. The new technique allows researchers to label and track individual molecules in three dimensions in living cells. Another new technique presented this week focuses on the molecular interactions between viruses and host cells. Known as the Protein Interaction Network Generator (PING) system, it has the ability to monitor thousands of potential interactions simultaneously and detect them with a 100- to 1,000-times greater sensitivity than current methods. A safe, 'self' virusResearchers have found a way to avoid the immune system's reaction to viruses used to deliver drugs to target tissues -- make them look like their part of the body. They engineered a lentivirus that expresses a self-marker known as CD47 on its surface, and confirmed its expression by tagging the marker with green fluorescent protein."This marker of self protein is found on all of our cells and tames our immune system," said University of Pennsylvania professor and senior study author Dennis Discher. This means that the immune system should theoretically ignore the virus, allowing it to "maximize the dose delivered to a tumor or diseased tissue."
**__Related stories:__***linkurl:News from AAAS;https://www.the-scientist.com/news/display/57994/
[21st February 2011]*linkurl:Lit Lazarus worms;https://www.the-scientist.com/2010/2/1/17/1/
[February 2010]*linkurl:New tool sheds light on cell imaging;https://www.the-scientist.com/blog/display/55180/
[10th November 2008]

Meet the Author

Jef Akst

Jef (an unusual nickname for Jennifer) got her master’s degree from Indiana University in April 2009 studying the mating behavior of seahorses. After four years of diving off the Gulf Coast of Tampa and performing behavioral experiments at the Tennessee Aquarium in Chattanooga, she left research to pursue a career in science writing. As The Scientist's managing editor, Jef edited features and oversaw the production of the TS Digest and quarterly print magazine. In 2022, her feature on uterus transplantation earned first place in the trade category of the Awards for Excellence in Health Care Journalism. She is a member of the National Association of Science Writers.

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