Genetic mutations strengthen functional association of LAP1 with DYT1 dystonia and muscular dystrophy

Publication date: Available online 5 August 2015 Source:Mutation Research/Reviews in Mutation Research Author(s): Sandra Rebelo, Edgar F. da Cruz e Silva, Odete A.B. da Cruz e Silva Lamina-associated polypeptide 1 (LAP1) is a ubiquitously expressed integral protein of the inner nuclear membrane. It interacts physically with lamins, torsinA, emerin and protein phosphatase 1; potentially providing a pivotal mechanism for transducing signals across the inner nuclear membrane. In neurons a functional protein complex is formed, comprising LAP1 and torsinA and in skeletal muscle LAP1 and emerin likewise form a protein complex. Several isoforms of LAP1 have been reported across species. However, in humans only two isoforms have been described, LAP1B and LAP1C. The latter has only recently been reported, but its physiological function and mode of action are not clear. The first TOR1AIP1 (gene encoding LAP1) mutation identified is a single nucleotide deletion resulting in a frameshift and a putative truncated LAP1B protein (Turkish mutation). This has deleterious effects associated with a specific form of muscular dystrophy. A second point mutation, affecting both human LAP1 isoforms, was also recently described. This mutation involves the replacement of a single glutamic acid to alanine at position 482 (Moroccan Mutation), thereby causing severe dystonia, cerebellar atrophy and cardiomyopathy. This review focuses on the recently described human LAP1 isoform (LAP1C), the two...
Source: Mutation Research Reviews in Mutation Research - Category: Genetics & Stem Cells Source Type: research