gWhat is Calmodulin's Function?
To bind calcium and activate other proteins important in glycogen and cell interactions.
  
(image taken from pdb file)
 Once calmodulin binds calcium, it forms a crucial subunit for the enzyme phophorylase kinase, which is a regulator for glycogen breakdown. But calmodulin also activates other kinases and phosphatases that then participate in cell signaling, ion transport, and cell death. So not only does calmodulin signal calcium levels, it also activates proteins for other various reactions!