Mary Cullinane has been named chief content officer and executive v-p of corporate affairs at Houghton Mifflin Harcourt. She joined the company in 2012.
Ann Treistman is joining Countryman Press, a division of W.W. Norton, as senior editor. Most recently, she was with Skyhorse Publishing.
Caroline Riordan is digital business director at Penguin. She previously worked for Hyperion as senior manager of e-books and business development.