WILTIMS #166: Highlighter Syndrome

This is turning into a pet peeve of mine: our pharmacology course director has a habit of sequentially highlighting every. Single . WORD. Sure, he never forgets to mention anything, but I'm so distracted by the lack of logic in his color choices that I stop paying attention.

Moving on.

At some point in one of our pharm lectures today, the Janus kinase (or JAK) was used as an example. Intrigued by the apparent devine reference I Googled the enzyme to learn it's etymology. TIL, JAK was always this enzyme's acronym, but the very apt Janus moniker was an afterthought. Initially the members of this enzyme class were known as Just Another Kinase I and II or JAK I/II. Classic biologist naming eccentricities, but atypically, they quite elegantly renamed these kinases to after the two-faced Roman god.

Janus is one of the few unique gods of the generally Greek-derived Roman pantheon. He is the god of transitions and is often used to symbolize dichotomies due to his two-faced appearance. The Janus kinase takes this name because it contains two kinase domains: one readily phosphorylates substrates while the other turns off the first.

Next, it can be useful to have a really bad, poorly-binding agonist (enzyme promoter) to be used as a long term antagonist (enzyme demoter) because you avoid upregulation (creating more enzymes). Let's break this down a bit: If you want a drug that turns off a particular enzyme, you might try... well... turning off the enzyme. The problem is the body is too smart for that and will respond by producing more and more enzymes. Eventually you can't overcome the upregulation.

So instead, you can use a chemical that actually promotes the enzyme, but way less effectively than the body's natural promoters. This, in effect, slows down the enzyme. And if the chemical binds weakly enough, it won't actually trigger the production of more enzymes.

Lastly, there is hope of creating a cancer vaccine by selectively turning off part of the safety mechanism that the body uses to make sure that the T cells of the immune system don't target the body's own cells.