David Sabatini Appointed to Whitehead Faculty

CAMBRIDGE, Mass. — The Whitehead Institute recently welcomed David Sabatini as its newest faculty member. Sabatini, who joined the Institute in 1997 as a Whitehead Fellow, was named an Associate Member at Whitehead and an Assistant Professor in the biology department at MIT.

Sabatini is interested in the basic mechanisms that regulate growth, the process whereby cells accumulate mass to increase in size. His work has been focused in part on a cellular system called the TOR pathway, a critical regulator of growth in many species. Earlier this year his lab identified raptor, a long-sought after protein component of this pathway.

Sabatini is one of a new cadre of researchers focusing on more than just basic biology. In their quest to decipher the molecular pathways that regulate cell growth, the Sabatini lab has worked to develop the technologies needed to study the functions of large sets of genes in mammalian cells. It was this brand of innovation that prompted MIT’s Technology Review to name Sabatini one of the world’s 100 Top Young Innovators in 2002.

“As a Whitehead Fellow, David Sabatini dazzled us with his deep thinking, innovative style, and technological savvy,” says Whitehead Director Susan Lindquist. “His work truly exemplifies the creativity that is needed to tackle the most fascinating biological questions. He is incredibly talented and we are thrilled to now welcome him aboard as faculty.”

Cell Microarrays

In his study of cell growth, Sabatini has focused in particular on how a drug called rapamycin, an immunosuppressant drug used to prevent organ rejection in kidney transplants, affects the biochemical pathways controlling cell growth. In early work with rapamycin, Sabatini identified a key protein, mTOR, involved in this pathway. When rapamycin blocks the activity of mTOR in special immune cells responsible for organ rejection, the cells stop growing and dividing in the body.

To study the mTOR pathway and other important cellular mechanisms, the Sabatini lab has developed a new type of cell microarray that allows scientists to look at thousands of proteins at once and identify their roles inside the cell. The microarrays, glass slides about half the size of a small business card, are covered with 10,000 microscopic spots, each composed of a group of live cells producing a specific protein. The result is a slide representing 10,000 different proteins. Sabatini envisions eventually having the entire set of human proteins available on a handful of slides.

These cell microarrays can be used to find proteins involved with cell growth, cell migration, or cell death, for instance. Alternatively, cell microarrays can be used in drug discovery to understand how drugs with unknown mechanisms affect cells and to identify a drug’s protein targets.

Sabatini’s work dovetails well with other work at the Institute. The lab is now collaborating with Whitehead Fellow Brent Stockwell to extend the microarray-based system to screening small molecules in mammalian cells.

“Whitehead is a terrific place to do science,” says Sabatini. “I am tremendously grateful for the opportunity to work with so many talented people.”

Sabatini, a graduate of Brown University, was appointed a Whitehead Fellow in September 1997 after completing the MD/PhD program at Johns Hopkins University School of Medicine. His honors and awards include the Medical Scientist Training Program Award from 1990 to 1997, and the Michael A. Shanoff Award for Thesis Research at Johns Hopkins.