Complex sentence: Calmodulin (CaM) is a calcium-binding protein that is expressed in all eukaryotic cells and can bind to and regulate a number of different protein targets, thereby affecting many different cellular functions.
Split into simpler sentences: Calmodulin (CaM) is a calcium-binding protein expressed in all eukaryotic cells. It can also bind to and regulate a number of different protein targets, thereby affecting many different cellular functions.