Ian Gibbons moved to Hawaii for one major reason: the sea urchins. In the warm tropical waters, they are always fertile, allowing year-round study of their highly mobile sperm – and the motors that he discovered power their tails and propel them through the water.
The discovery of that molecular motor this week earned Gibbons, a longtime visiting scholar at UC Berkeley, the prestigious Shaw Prize in Life Science and Medicine, awarded each year by the Shaw Prize Foundation of Hong Kong. He will share the $1.2 million prize with Ron Vale, a professor of cellular and molecular pharmacology at UC San Francisco, who followed in Gibbons’ footsteps and discovered a second molecular machine that moves things around inside the cell.
The two were cited “for their discovery of microtubule-associated motor proteins: engines that drive nerve cell growth and chromosome inheritance essential to human development.”
Gibbons first heard about the honor when Vale called him Tuesday morning to congratulate him, some 10 hours after the award was announced in Hong Kong.
His first reaction was “amazement that anyone still remembers me. History is history,” said Gibbons, now 85. “But I think it’s a very logical that Vale and I received the prize together. Ron discovered the second motor protein family responsible for moving bits and pieces of a cell around on microtubules within the cytoplasm. I discovered dynein, he discovered kinesin.”
The protein motor dynein that Gibbons discovered and named after the metric unit of force, the dyne, is what makes the tails of sperm and the flagella of protozoa undulate and the cilia covering other tissues ripple. In the 1960s, the question he asked was, how can simple proteins produce a force that can push cells through the water?
The answer, he discovered, was a protein that forced the individual microtubules – long protein rods – in a bundle to slide past one another, generating a force that, in differing spatial arrangements, can not only whip a sperm tail, but can also push and pull on the skeleton of the cell, even to the extent of pulling it apart to form two daughter cells.
“At the time, it was new, it was one of the first proteins to be isolated from the inside of a cell purely on the basis of its possible functioning in motility, apart from muscle proteins, which had been known for quite a lot longer,” he said.
From protozoa to sea urchin sperm
A native of England, Gibbons studied physics at the University of Cambridge, obtaining a Ph.D. in biophysics in 1957, and took a position at Harvard University in 1958 as head of its electron microscope lab. In the time alotted for his own research, he used the electron microscope to study the flagella of single-celled protozoa from the guts of termites, and published the first images of a huge new protein on microtubules in 1963. Two years later, in 1965, he showed that the biochemical properties of this new protein were those expected for a molecular motor and named it dynein.
But images alone could not prove that dynein actually produced movement. He spent the next 20 years solidifying his argument, first at Harvard, and after 1967 at the Kewalo Marine Laboratory, which is part of the Pacific Biosciences Research Center operated on Oahu by the University of Hawaii at Manoa. In Hawaii, he found sea urchin sperm tails much easier to obtain and work with, and with his wife Barbara, a biochemist, eventually showed during the 1970s that dynein combined with an energy source – ATP (adenosine triphosphate) – was necessary and sufficient to make microtubules move.
He and his wife continued to explore dynein, using new techniques such as gel electrophoresis and the polymerase chain reaction, which allowed them in the early 1990s to determine a complete sequence for the largest protein subunit forming the dynein motor.
“This opened dynein to study by molecular biological procedures in many laboratories, rapidly revealing the highly conserved structure and broad functional importance of the dynein motor family in eukaryotes,” according to a citation from the Royal Society, which elected him a fellow in 1983.
Researchers, including Gibbons, have discovered numerous members of the dynein family. There are 15 varieties in humans, all a bit different, he said.
Gibbons directed the Kewalo Marine Lab from 1993 until 1996 and retired in 1997, when he was offered space as a visiting scholar in the UC Berkeley laboratory of Beth Burnside, a professor emerita of molecular and cell biology and former vice chancellor for research. There he began using X-ray crystallography to explore the three-dimensional atomic structure of dynein.
In the early 2000s, 40 years after discovering dynein, Gibbons and his Berkeley postdoc Joan Garbarino collaborated with Vale and Andrew Carter at UCSF to establish the 3D structure of the motor’s microtubule binding domain, and described the sliding coiled-coil mechanism that is involved in modulating dynein’s affinity for microtubule binding during its mechanochemical cycle.
Since Burnside closed her lab in 2009, Gibbons has been working at his home in Orinda, California, on a book about the history of dynein research.
A citizen of the United Kingdom, Gibbons and his wife raised two children, Wendy and Peter, both of whom live in the Bay Area. Barbara Gibbons died in 2013.
Gibbons has also been awarded the 1988 Lezioni Lincei of the Academia dei Lincei in Rome, the 1994 E. B. Wilson Medal of the American Society for Cell Biology (with Barbara Gibbons), and the 1995 Japanese International Prize for Biology.
The Shaw Prize was established under the auspices of the late Run Run Shaw, a Hong Kong film and television entrepreneur and philanthropist, in November 2002. The foundation sponsors three annual $1.2 million awards: the Prize in Astronomy, the Prize in Life Science and Medicine and the Prize in Mathematical Sciences.
The 2017 astronomy prize went to Simon White, director of the Max Planck Institute for Astrophysics in Germany, for his contributions to understanding structure formation in the universe. The math prize went to János Kollár of Princeton University and Claire Voisin of the Collège de France for their work in algebraic geometry. They will receive their awards during a ceremony scheduled for Sept. 26.