Palade, George (1912- )

Romanian cell biologist who was awarded a Nobel Prize for Physiology or Medicine in 1974 with Albert Claude and Christian René de Duve for work on the structural and functional organization of the cell. Palade determined the parts of the cell involved in protein secretion, and discovered ribosomes, which he showed to be rich in RNA, or ribonucleic acid (nucleic acid involved in the process of translating genetic material into proteins).

Cell research Palade developed a method called cell fractionation, in which elements of the cell are labelled with radioactive molecules and then segregated by breaking the cell apart and spinning down the organelles to isolate them from one another. He used this technique, along with electron microscopy, to look inside whole preserved cells and describe the organelles involved in the secretion of proteins, especially in cells that are specialized for the secretion of enzymes.

The cytoplasm (the part of the cell outside the nucleus) of these cells is packed with endoplasmic reticulum studded with ribosomes, which Palade correctly determined were involved in protein secretion. He elucidated that the protein is made on the ribosomes, moved into the interior of the endoplasmic reticulum and from there to a series of flattened sacs in the cytoplasm, called the Golgi apparatus. He observed that the protein was then pushed into small vesicles and that these were then moved to the cell surface to secrete their protein contents.

Life Palade was born in Iassy in Romania and trained as a doctor in Bucharest. He worked as professor of anatomy in Bucharest before emigrating to the USA in 1946 to take up a staff position at the Rockefeller Institute in New York. He was elected to the chair of cell biology at the medical school of Yale University in 1972 and then the chair of cellular and molecular biology at the University of California in 1990.