When living in Chicago, we would often get off on the 31st Street exit on Lakeshore Drive, and at the time there was a sign pointing out some parking areas for McCormick Place. I recall specifically that two of those were labeled "E2" and "E3" and being the gigantic nerd that I am, thought immediately of ubiquitin. Since it is found in every type of cell in all eukaryotic cells, the protein is appropriately named. Check out the cool ribbon model I made of ubiquitin for my students once upon a time, and then let's take a look at ubiquitin's functions in living organisms and how it contributes to health and disease.

When I taught high school biology, a favorite part of the curriculum was cellular structures and functions. I set up an activity suggested by other experienced biology teachers that was based on the “Cell City,” a learning analogy where students would create an artwork of a city with the mitochondrion as a power plant and a vacuole as a lake. (Figure 1) I wish I saved their very creative projects, but I distinctly remember one group used the Chicago Transit Authority’s elevated train system map to represent the endoplasmic reticulum (ER), a very clever use of the analogy and a nod to city pride. It was also the first time these students really thought about vesicular transport, although they didn't fully understand its importance.