Isolation and characterization of the complete mouse emerin gene

Emery-Dreifuss muscular dystrophy (EMD) is an X-linked recessive disorder associated with muscle wasting, contractures, and cardiomyopathy. The responsible emerin gene has recently been identified and found to encode a serine-rich protein similar to lamina-associated protein 2 (LAP2), although the disease mechanism remains obscure. In order to pursue the pathophysiology of this disorder, we report here the isolation and characterization of the complete mouse emerin gene. The emerin cDNA was isolated from murine strain BALB/c, and the emerin gene was isolated from strain 129. The 2.9-kb mouse emerin gene was completely sequenced and found to be composed of 6 exons and encode a protein 73% identical to that of the human protein. Key similarities with LAP2 were found to be conserved, including critical LAP2 phosphorylation sites. Examination of the murine promoter revealed three previously unrecognized cAMP response elements (CRE) conserved between human and mouse. While Northern analysis shows emerin to be widely expressed in the mouse, as it is in humans, these promoter elements may indicate cAMP responsiveness. These data provide the necessary elements to further investigate EMD in a murine system.