Fri 21 Jun 2013
By Aviva Rutkin
Nobel Prize winner Rod MacKinnon had his lunch table rapt.
He was describing a kayaking trip he’d taken a few years earlier. After flipping his boat right-side-up to correct an accidental roll, MacKinnon discovered that he’d narrowly missed sharing the water with a six-foot shark. He watched, frozen in place, as the beast hunted down an unlucky seal. As MacKinnon relayed the tale, graduate students stared at him from around the table, their mouths agape.
This anecdote marked the end of MacKinnon’s annual visit to the MBL’s Neurobiology course to lecture about his area of specialty, potassium channels. The class, which features lectures from numerous visiting scientists, is co-directed by UCSF’s Graeme Davis and Cornell’s Timothy Ryan.
“I love coming back here,” MacKinnon said. “It’s a nice opportunity to teach [students] about your own field and maybe turn on some bright scientists to the stuff you like.”
MacKinnon has been around the MBL for “my whole career,” he says. He first visited the MBL as a post-doc in 1985, shortly after he had decided to pursue a career in research rather than medicine. One of his former professors, Brandeis biochemist Chris Miller, invited MacKinnon to help teach a two-week section on electrophysiology.
Since then, MacKinnon has become internationally recognized for his work on potassium channels, the pathways that potassium ions use to enter the cell. The concentration of such ions inside the cell is crucial in the regulation of many different functions, including neuron firing. In the late 1990s, MacKinnon’s laboratory discovered the structure of these channels using X-ray crystallography. This research helped to explain why the channels admitted potassium ions while blocking much smaller sodium ions. MacKinnon was awarded the Nobel Prize in Chemistry for this work in 2003.
MacKinnon’s Neurobiology lecture at the MBL this year followed the arc of scientific discovery. Using handwritten slides, MacKinnon walked the students through the different questions that scientists had faced when studying these elusive channels. How did they know that the channels were there? How might they divine how the channels functioned? Was there an upper limit on how much potassium could move through at a given time?
“I find it’s easy to learn science if you know the questions that people were faced with at the time,” he explained. “Once it’s all figured out, the synopsis is made and then that’s what future generations learn. But sometimes that synopsis by itself is harder to understand out of the context of the questions at time, so it’s nice to trace the history of how something came to be understood. Once you know that, it’s much easier to understand the concept, and much easier to remember.”
After the lecture, MacKinnon followed the students to lunch at Swope, where they chatted about his views on science and the different research projects the students were involved in. He also shared some his favorite places in the area to grab a bite – and to go kayaking.
“It’s a great honor to see a Nobel Laureate speak,” said Cliff Woodford, a chemistry graduate student from UCSD. “It makes you feel like what you’re doing is important when you get to see the giants in the field.”