How Some Cancers Infect Cells.

• Position: Research findings - Brief Article

Researchers at Purdue University, West Lafayette, Ind., have identified the role of a protein segment that allows some cancer-causing viruses to latch onto and infect cells. Analysis of the protein segment--which bears a striking resemblance to bee venom--may increase scientists' understanding of how retroviruses and some other viruses enter cells. The work may lead to new therapies aimed at thwarting such viruses. (Retroviruses can cause tumors and leukemia in animals and humans. The AIDS virus is a retrovirus.)

"The new data have important implications not only for the membrane fusion processes that lead to the entry of retroviruses and other viruses such as influenza viruses and the Ebola virus, but also to normal cellular processes such as fertilization of an egg by a sperm," notes David Sanders, an assistant professor in the Department of Biological Sciences.

Working with doctoral student Gwen Taylor, he discovered the importance of an amino acid sequence which is part of a protein that was previously thought to be unassuming. Their study shows this segment of the protein is essential for membrane fusion, and that changing just one amino acid in the sequence could eliminate fusion between the virus and its host. The findings may lead to novel treatments to block the entry of retroviruses and other membrane-possessing viruses.

The proteins that stud the membrane surrounding a retrovirus--called envelope proteins--allow the virus to bind to a host cell and promote the fusion of the virus and cell membranes. It is through this fusion process that the virus enters the cell. Although the process of cell fusion has long been recognized, the structure of these membrane-spanning proteins include regions...