Characterization of cardiac muscle factor 1 sequence motifs: retinoblastoma protein binding and nuclear localization.

Cardiac muscle factor 1 (CMF1) is characterized as a protein important in cardiac and skeletal myocyte differentiation and is expressed in a developmentally regulated manner. Sequence analysis data showed that CMF1 has crucial protein-protein interaction domains, has a retinoblastoma protein-binding site which interacts with RB directly in vitro and in the embryo, has a functional nuclear localization signal and is highly homologous to other cell cycle regulatory proteins such as mitosin and centromere protein F, which suggests that CMF1 may be involved in regulating the cell cycle.