Tropoelastin heterogeneity: implications for protein function and disease.

The organization of the tropoelastin gene is similar to that of other genes coding for matrix proteins in that the exons code for distinct domains of the protein. An unusual feature of tropoelastin expression is that the primary transcript of the gene coding for tropoelastin undergoes extensive, developmentally regulated alternative splicing, resulting in numerous protein isoforms. Although the significance of this heterogeneity is unknown, the multiple sequence variations may affect the function of tropoelastin. Without an understanding of the importance of the domains of tropoelastin and the process of fibrillogenesis, characterization of defects resulting in aberrant elastin production will be hindered. In this update, we review recent findings on tropoelastin and speculate as to the structural and regulatory role of various regions of this matrix protein.