Helping cells achieve oneness

Yeast do it. So do muscle cells and sperm and eggs. All of these cells can abandon their individuality and fuse. Heiman et al. report on page 209 that they've pinpointed a protein that helps bring yeast together, a finding that helps to clarify the murky mechanism of cell fusion.

A complex of membrane fusion proteins is deployed by an influenza virus as it invades its host cell. But the comparable machinery of most eukaryotic cells that fuse has not been identified. Several years ago, the group identified one protein crucial for the process by studying yeast mating, in which two fungal cells stick together, dissolve their cell walls at the point of contact, and join their membranes. Yeast missing the protein Prm1 snuggle up to one another but often can't unite, the researchers found.

But...