Abstact

Proteins of the A-type lamin family, which consists of two members, lamin A and lamin C, are the major components of a thin proteinaceous filamentous meshwork, the lamina, that underlies the inner nuclear membrane. A-type lamins have recently become the focus of extensive functional studies as a consequence of the linking of at least eight congenital diseases to mutations in the lamin A/C gene (LMNA). This spectrum of pathologies, which mostly manifest themselves as dominant traits, includes muscle dystrophies, dilated cardiomyopathies, the premature aging syndrome Hutchinson-Guilford progeria and familial partial lipodystrophy (FPLD). The crystal structure of the lamin A/C mutant R482W, a variant that causes FPLD, has been determined at 1.5 A resolution. A completely novel aggregation state of the C-terminal globular domain and the position of the mutated amino-acid residue suggest means by which the mutation may affect lamin A/C-protein and protein-DNA interactions.