Named after the fearsome dragon in JRR Tolkien’s fantasy novel The Hobbit, Smaug is the fiery foe that drives out the dwarves of Erebor from their caves under the Lonely Mountain. And then he sits there, on a massive pile of gold, until Bilbo Baggins and a bunch of dwarves turn up and kill him.
Just as Smaug the dragon inhibits the activities of the dwarves of Erebor, the fruit fly gene Smaug encodes a protein that inhibits the activity of another gene called Nanos, which is the Greek word for dwarf. It does this by binding to the message made when the Nanos gene is read - known as messenger RNA - and stopping it from being translated into a protein, but only when the Nanos RNA is in the wrong place in a fruit fly embryo. If this interaction doesn’t happen, then Nanos is made where it’s not needed, leading to stubby little maggots growing instead of elegant long ones.
Smaug is also found in mammals, and is often found located in small granules at the junctions, or synapses, between nerve cells, where it also stops messenger RNA being translated into proteins. It’s not entirely clear what its role is, but Smaug and other proteins that control message translation are thought to be involved in memory formation. So maybe my Smaug proteins are helping me to remember the plot of The Hobbit.