Emerin

Emerin encoded by the STA gene is the first nuclear protein linked with a m uscular dystrophy. Emerin is a 34 kDa, predominantly hydrophilic protein wi th a single hydrophobic region supposed to serve as a transmembrane domain. It was classified as a type II integral membrane protein localized at the inner nuclear membrane/nuclear lamina with an ubiquitous tissue distributio n. It is speculated that emerin is required for the stability and normal fu nction of rigorously moving nuclei in skeletal muscle and heart. During mit osis, emerin is cell-cycle-dependent phosphorylated and shows stage-depende nt changes in distribution and localization suggesting that it plays a role in re-assembly of nuclear membranes. Mutations of the emerin gene have bee n associated with X-linked Emery-Dreifuss muscular dystrophy clinically def ined by early joint contractures, progressive muscle weakness, and cardiomy opathy. Hopefully, identification of the protein defect may promote new the rapeutic strategies concerning muscle fiber development and stability. (C) 1999 Elsevier Science Ltd. All rights reserved.