The Protein’s in the Mail

A busy urban post office daily sorts thousands of letters and parcels, guiding each to a particular mailbox somewhere in the city. Each day, every cell of the human body manufactures millions of proteins, which it also must continually sort, and route to their final destinations within the cell. Only when a protein has reached its destination can it do its assigned work.

But just how do the proteins get where they need to go? Rockefeller University Professor Günter Blobel, an investigator of the Howard Hughes Medical Institute, won the 1999 Nobel Prize in Physiology or Medicine for discovering that each cell uses a “ZIP Code”-like system to shuttle proteins to their intended destinations. Now, new research from Blobel’s Laboratory of Cell Biology, reported in a recent issue of Cell, provides a more detailed picture of the “sorting” mechanism used in the cell’s “post office.”#