What do you do after founding one of the most beloved bands ever? If you’re Carrie Brownstein, you become the star of “Portlandia” and satirize one of the most beloved cities. Also, former “Saturday Night Live” political writer Jim Downey explains how a sketch comedy show came to shape American political discourse. Plus, how the novelist Emma Donoghue adapted her bestselling novel, “Room,” into a movie — with a little help from director Lenny Abrahamson.