Allison Janney has joined the cast of the musical comedy, Hairspray for New Line Cinema; she's also made a deal to develop a sitcom at CBS.

Janney will start rehearsals on the film immediatly, says Variety; she'll play Prudy Pingleton, the overbearing mother of Penny (Amanda Bynes) who believes that dancing and having fun is sinful.

The star-studded cast of Hairspray includes John Travolta, Queen Latifah, Christopher Walken, Bynes, Michelle Pfeiffer, James Marsden, Zac Efron and Nikki Blonsky.

Shooting on Hairspray begins next month for a 2007 release.

On the TV side, Janney's deal with CBS is to produce a sitcom for the fall 2007; no details were given as to the plot.

Hairspray was released July 20th, 2007 and stars John Travolta, Michelle Pfeiffer, Christopher Walken, Amanda Bynes, James Marsden, Queen Latifah, Brittany Snow, Zac Efron. The film is directed by Adam Shankman.