November 5, 2007

Three Salk scientists named 2007 AAAS Fellows

Salk News

Three Salk scientists named 2007 AAAS Fellows

LA JOLLA, CA—Professors Ursula Bellugi, Walter Eckhart and Greg E. Lemke have been awarded the distinction of AAAS Fellow, an honor that is bestowed upon members of the American Association for the Advancement of Science by their peers.

Bellugi, who heads the Laboratory for Cognitive Neuroscience at the Salk Institute for Biological Studies, has been selected for her fundamental research in the neurobiology of signed and spoken languages, and for her innovative characterization of Williams syndrome as a model for human cognition.

Bellugi, who established her lab at the Salk in 1970, is regarded as the founder of the neurobiology of American Sign Language since her research revealed the existence of primary linguistic systems that are passed down from one generation of deaf people to the next which have been forged into a complexly structured language with complex grammatical properties not derived from spoken languages. Her work has led to the finding that the left hemisphere of the human brain has an innate predisposition for language, even for a language in which spatial and visual processing plays a central role.

During her career, Bellugi has been seeking new avenues for understanding the ties between molecular genetics, the brain and cognition. This led her to Williams syndrome, a condition in which almost invariably the same set of about 20 genes is deleted from one copy of chromosome seven, making it a unique model system to study how a genetic predisposition interacts with the environment to sculpt the brain in unique ways. With unflagging enthusiasm, Bellugi moves closer to understanding how missing genes and the resulting changes in brain structure and function ultimately shape behavior.

Eckhart, director of the Salk Institute Cancer Center and head of the Molecular and Cell Biology Laboratory, has been selected for the characterization of cell transformation by polyomavirus and the co-discovery of protein tyrosine phosphorylation.

Eckhart came to the Salk in 1965 as a postdoctoral fellow to work in Nobel Laureate Dr. Renato Dulbecco’s laboratory. Five years later he was appointed to the Institute faculty. He and his colleagues worked to understand how DNA tumor viruses cause malignant cell transformation. Using a combination of genetic and biochemical techniques, they identified the functions of cancer causing genes, so called oncogenes, of polyomavirus, including a function required for viral DNA replication and a function that stimulates cell growth by mimicking an activated growth factor receptor.

Eckhart and his Salk colleague Tony Hunter, a professor in the Molecular and Cell Biology Laboratory, found that the viral “growth factor receptor” was associated with an activity that added phosphate to tyrosine (tyrosine phosphorylation). Tyrosine phosphorylation is now recognized to be a central controlling mechanism for many cellular processes.

More recently, Eckhart’s laboratory studied the effects of viral oncogenes on communication between adjacent cells, leading to loss of growth control and cancer. They also characterized growth signaling through the Type I insulin-like growth factor receptor using three-dimensional cultures of human mammary epithelial cells, which led to the discovery that activated growth factor signaling produces changes characteristic of pre-malignant breast cancer.

Lemke, a professor in the Molecular Neurobiology Laboratory, is recognized for his distinguished contributions to our understanding of the roles receptor tyrosine kinase pathways play in regulating neural and immune development.

Lemke joined the ranks of Salk faculty in 1985 and most of his work has focused on intercellular communication that is mediated by cell surface receptors, termed “receptor tyrosine kinases” (RTKs). In the mid-1980s, he purified a growth factor named neuregulin-1, which activates RTKs of the ErbB family. These receptors play important roles in a wide diversity of biological processes, and one of them – ErbB2 – is a prominent component of many breast cancers.

His laboratory has also used molecular genetics to elucidate the role that a second set of RTKs – the EphA receptors – play in the ordered wiring of connections between nerve cells in the developing brain. Most recently, he and his colleagues have identified a third set of RTKs – the TAM receptors – that play essential roles in retinal maintenance and in immune system regulation. In the immune system, the TAMs function as key inhibitors of inflammation.

This year’s AAAS Fellows were announced in the AAAS News & Notes section in the Oct. 26, 2007 issue of the journal Science. The new Fellows will be honored on Feb. 16 during the 2008 AAAS Annual Meeting in Boston.

The tradition of AAAS Fellows began in 1874. Currently, members can be considered for the rank of Fellow if nominated by the Steering Groups of the Association’s 24 sections, or by any three Fellows who are current AAAS members (so long as two of the three sponsors are not affiliated with the nominee’s institution), or by the AAAS Chief Executive Officer.

Each Steering Group then reviews the nominations of individuals within its respective section and a final list is forwarded to the AAAS Council, which votes on the aggregate list.

The Council is the policymaking body of the Association, chaired by the AAAS President, and consisting of the members of the Board of Directors, the Retiring Section Chairs, delegates from each electorate and each regional division, and two delegates from the National Association of Academies of Science.

The Salk Institute for Biological Studies in La Jolla, California, is an independent nonprofit organization dedicated to fundamental discoveries in the life sciences, the improvement of human health and the training of future generations of researchers. Jonas Salk, M.D., whose polio vaccine all but eradicated the crippling disease poliomyelitis in 1955, opened the Institute in 1965 with a gift of land from the City of San Diego and the financial support of the March of Dimes.

The American Association for the Advancement of Science (AAAS) is the world’s largest general scientific society, and publisher of the journal, Science ( AAAS was founded in 1848, and includes some 262 affiliated societies and academies of science, serving 10 million individuals. Science has the largest paid circulation of any peer-reviewed general science journal in the world, with an estimated total readership of 1 million. The non-profit AAAS ( is open to all and fulfills its mission to “advance science and serve society” through initiatives in science policy; international programs; science education; and more. For the latest research news, log onto EurekAlert!,, the premier science-news Web site, a service of AAAS.

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