Anthony P. Bretscher
Cellular and Developmental Biology, Microbiology, and Immunology (including Genetics)
World leader in the study of microfilaments. He was the first to isolate a defined microfilament-based structure, the microvillus, leading to the discovery and characterization of founding members of several protein families, including the F-actin severing protein villin, the bundling protein fimbrin, the membrane-microfilament linkers myosin-I and ezrin, and the scaffolding and regulatory proteins EBP50 and EPI164. In parallel pioneering studies in budding yeast, Bretscher uncovered how growth is polarized and organelles segregated during the cell cycle, including the discovery that formin proteins nucleate F-actin assembly, and how a molecular motor, myosin-V, delivers cargo.