LEK1 protein expression in normal and dysregulated cardiomyocyte mitosis.

A defining characteristic of embryonic cells is their ability to divide rapidly, even in tissues such as cardiac muscle, which cannot divide once fully differentiated. This suggests that regulators of cell division differ in embryonic and differentiated cells. LEK1 is a member of an emerging family of proteins with diverse functions but shared structural domains, including numerous leucine zippers, a nuclear localization site, and a functional Rb-binding domain.

Ligand-specific control of src-suppressed C kinase substrate gene expression.

The src-suppressed C-kinase substrate, SSeCKS, is now recognized as a key regulator of cell signaling and cytoskeletal dynamics. However, few ligands that control SSeCKS expression have been identified. We report that platelet-derived growth factor-BB (PDGF-BB), lysophosphatidic acid (LPA), and eicosapentaenoic acid (EPA) potently modulate SSeCKS gene expression in cultured smooth muscle (RASM) cells relative to other bioactive ligands tested.