Z-line proteins:: implications for additional functions

Z-Iine proteins have important structural functions. However, recent publications point to additional, previously unexpected functions and a new view is now emerging, whereby these proteins are involved in important intra- and inter-cellular signaling pathways. Their translocation to the nucleus, the interaction with other signaling molecules and the ability to facilitate macromolecular protein complexes indicate the multi-functionality of Z-Iine proteins. A better understanding of these emerging physiological 'roles of Z-Iine proteins might be achieved by precise investigations of specific mutations in specific domains in a subset of these proteins. Clues will be given to explain the clinical variations in the development and severity of different forms of cardiomyopathies, which are also affected by genetic redundancy and ethnic background of different patient populations.