C/EBPα functional and protein interaction domains. Above the diagram, the amino terminal transactivation domains are marked, defined by 2 previous studies: TE-I, TE-II, and TE-III¹² ; and TAD1 and TAD2.¹¹  Numbers directly above the diagram indicate the amino acids corresponding to TE-II (70-97), TE-III (127-200), and the basic-zipper domain (bZip; amino acids 278-358 of the rat C/EBPα protein¹⁰ ). Also shown are the positions of the ATG start translation site for the 42-kDa wild-type C/EBPα peptide as well as the start ATG encoding the 30-kDa peptide (at amino acid 120). Below the diagram are the locations of interaction of the retinoblastoma protein (“RB,” amino acids 68-83⁵⁰ ); the cell cycle inhibitor p21 (“p21,” amino acids 119-226 and the leucine zipper, amino acids 313-360⁵¹ ); chromatin remodeling proteins (“SWI/SNF,” amino acids 126-200, corresponding to TE-III¹³ ); cyclin dependent kinases (“Cdk,” described in one study as amino acids 175-188,³⁵  and in another study as amino acids 119-160 and 280-313⁵¹ ); and E2F proteins (“E2F,” amino acids 294 and 297, this study). Shown below are the 42-kDa wild-type and mutant C/EBPα proteins used in this study. * Indicates the location of the 2 point mutations in each BRM mutant (BRM-2: Ile294Ala, Arg297Ala; BRM-3: Asp301Ala, Lys304Ala²¹ ).