Indy taught at Marshall in Raiders, at Barnett in Last Crusade, and back at Marshall in Crystal Skull. In regards to video games, he teaches at Barnett in Fate of Atlantis and LEGO Indiana Jones. I don't recall if the novels mention him teaching at either of these colleges.
Marcus was curator at the Metropolitan Museum in New York, and not affiliated with any schools. His museum simply financed Indy's expeditions in return for any artifacts Indy might find.