Under the Microscope: The TRiP to worms with Shawn Xu

There was never any doubt that out of more than sixty million people in Hubei Province in central China that Shawn Xu was an excellent student. His father was a math teacher and expectations were high for Xu, born Xian-Zhong Xu in the town of Shishou. Because of earning top grades, he was exempt from the Chinese national college and graduate school entrance exams required of most students to enter colleges and graduate schools.

"I was presented with two choices of study at that time like most other students—an engineer or a scientist," said Xu. With role models like Newton and Einstein, Xu decided to be a scientist. He attended Wuhan University and majored in biochemistry. "I was interested in biology because I was told that biology was the science for the 21st century," Xu explains.

He hoped to move to the US after earning his undergraduate degree in 1991, but it was difficult because of some government regulations at the time.

"Now it is completely open. Everybody is free to come to this country to study," said Xu.

"Here in the US, the universities are better evolved in terms of funding, equipment, and also communication. You are exposed to new advancements and knowledge such that you can catch up and move to the forefront immediately."

In graduate school, his thesis advisor received a grant at the National Laboratory of Biomacromolecules in Beijing to study the ATP (adenosine triphosphate) enzyme in wheat, so Xu moved to Beijing to conduct research on calcium regulation of the ATP pump, which provides energy for most of the activities of the cell.

Not willing to abandon his hopes to study in the US, after completing his master's degree, for the first time in his academic career, Xu was forced to face tests—the GRE and TOEFL. He became a PhD student at Johns Hopkins Medical School to study with Dr. Craig Montell, who pioneered the TRP (pronounced "trip") channel field, and Xu could see it was an emerging field.

"TRP channels allow ions including calcium to get into the cell and are involved in sensory physiology. For example, some TRP channels are gated by temperatures. You feel cold? That's because cold temperature activates your TRP channels. You feel warm? That is because some TRP channels are activated by warm temperature," explains Xu.

A funny thing happened on the TRiP to calcium. Xu became interested in genetics. As he learned at the bench, he realized the potential in genetic studies and wanted to use animal models to study TRP channel-mediated calcium signaling.

Once again, he was presented with two choices for conducting research: the fruit fly Drosophila or the nematode worm C. elegans. So upon completing his PhD, Xu determined to study the worm as a postdoc in Paul W. Sternberg's lab at Caltech.

"Craig introduced me into the TRP and calcium signaling field, and I am still influenced by his way of approaching science. Craig is a great mentor. So is Paul. He gave me complete freedom with whatever I wanted to do. His philosophy was to have good people, and let them go, so I was the only one studying calcium and ion channels," said Xu. Along the way Xu won accolades for young researchers, including a Harold Weintraub Graduate Student Award and Helen Hay Whitney Foundation Fellowship.

At UM, his research has focused on the TRP channels and their regulation of neuronal calcium signaling in the nervous system. His recent work using C. elegans reveals that these channels play a role in proprioception—often referred to as the sixth sense in humans or sensory awareness of the body.

"I started with calcium and the TRP channels evolved, and I got interested in the biology itself. So now in my lab we are really studying neuronal signaling and behavior, and no longer focusing on TRP channels alone," Xu said. "There are many channels and they are conserved from worms to humans. The science has evolved."

Xu moved to the LSI in January 2005 as research assistant professor. He is also assistant professor of Integrative and Molecular Physiology.