Two Yale professors have earned the Gairdner International Award, one of the most prestigious awards in medical science, Gairdner Foundation President Dr. John Dirks announced Friday.

Sterling professors Joan Steitz and Thomas Pollard will formally receive their awards Oct. 26 in Toronto. The two are among five winners this year, and won the prize for their pioneering work in understanding gene regulation and cell mobility, respectively. The 47-year-old award has previously been given to 279 scientists, 65 of whom have later won the Nobel Prize. Steitz traveled to Toronto yesterday to speak about her research.

Steitz’s influential work in gene regulation was the discovery of small particles combining RNA and proteins — called small nuclear ribonucleoproteins, or snRNPs — that splice out “junk” RNA, a crucial step in expression of proteins from genes. She made her breakthrough in 1979, nine years after joining the Yale faculty. Now a Sterling professor of molecular biophysics and biochemistry, Steitz is also an investigator with the Howard Hughes Medical Institute.

Pollard, chair of the Department of Molecular, Cellular and Developmental Biology since 2004 and a Yale biology professor since 2001, said the award was the product of a lifelong interest in the single broad problem of cell movement.

“I got into this when I was [in college] by looking at cells moving around under a microscope,” he said. “It was a big dream that we’d be able to understand how the system works. None of these molecules had been identified yet.”

Dr. Pollard’s award does not stem from a single discovery, but rather the culmination of decades of work studying the molecular underpinnings of cell mobility. Pollard will receive the Gairdner Award for dissecting a complicated system explaining cell motility, the same field explored by Alan Hall, now at Memorial Sloan-Kettering Cancer Center and another of this year’s award winners. The theory Pollard put forth eight years ago has stood up well, he said, and includes just six proteins interacting to regulate growth of filaments that grow out like branches on a bush to allow the cell to crawl. Cell mobility is important for studying immune response, since white blood cells are highly mobile, and development among other areas of scientific research, he said.

Steitz said her discoveries came from an unusual source for much of basic science research: Humans.

“Now there’s so much going on at the interface of biology and medicine,” she said. “But then there wasn’t as much. Almost no research went from the bedside to the bench.”

Most research that links basic science and clinical work, she said, involves taking discoveries made in the laboratory and applying them to human diseases. But in Steitz’s case, she made a serendipitous discovery, as she describes it, that patients with certain autoimmune diseases, including lupus, make antibodies against what are now known as snRNPs. She studied these complexes and determined that they play a role in gene regulation.

Some recent studies have suggested that splicing errors alone account for 10-15 percent of human genetic diseases.

Yale’s last Gairdner Award recipient came in 2004 when Dr. Arthur Horwich, professor of genetics and pediatrics and a Howard Hughes Medical Institute investigator, won it for his work on molecular chaperones, proteins that help other proteins be folded into the correct form.

Dirks said Steitz and Pollard rose to the top of a pool of about 100 nominated researchers.

“These are two very seminal areas, and where [Steitz and Pollard’s] contributions are of a very special and unique nature,” he said. “We just try to pick the best.”

Nominations come each November from a 22-member panel of Canadian scientists, which are then considered by the Foundation’s Medical Advisory Board. These scientists on the Advisory Board, who hail from Canada, the United States and the United Kingdom, consider each nominee and select three to six winners each year.