Cusack joins 'Shameless' cast

Joan Cusack has joined the cast of Showtime’s “Shameless.”

Actress plays a mom with a sexually active daughter, a role originally taken by Allison Janney in the pilot. Janney had to be replaced, however, because she landed a role in the ABC midseason series “Mr. Sunshine.”

“Shameless” is based on a U.K. series from Paul Abbott, who exec produces with John Wells. Bonanza Prods. is producing. Skein, which launches Jan. 9, stars Emmy Rossum and William H. Macy. Production begins in a few weeks.

Cabler also just signed Eddie Izzard to co-star in the third season of “United States of Tara.” Izzard will appear in eight episodes.

Izzard is no stranger to cable, having had a starring role in FX drama “The Riches.” He’s also performed in several stand-up specials.