| The protein uses two distinct regions to bind Rb and thyroid hormone receptor ( TR ) , respectively , and thus was named Trip 230 . ^^^ Trip 230 binds to Rb independently of thyroid hormone while it forms a complex with TR in a thyroid hormone dependent manner . ^^^ Coexpression of wild type Rb , but not mutant Rb that fails to bind to Trip 230 , inhibits such activity . ^^^ |