Loss of A-type lamins and genomic instability.

Research performed in the last few years has revealed important roles for the spatial and temporal organization of the genome on genome function and integrity. A challenge in the field is to determine the molecular mechanisms involved in the organization of genome function. A-type lamins, key structural components of the nucleus, have been implicated in the maintenance of nuclear architecture and chromatin structure. Interestingly, alterations of A-type lamins lead to defects in DNA replication and repair as well as gene transcription and silencing. Elucidating the functions of these proteins is a topical subject since alterations of A-type lamins are associated with a variety of human diseases, ranging from muscular dystrophies and premature aging syndromes to cancer. Here, we discuss novels roles for A-type lamins in the maintenance of telomere structure, length and function as well as in the stabilization of a key DNA damage response factor. These studies support the notion that increased genomic instability due to defects in telomere biology and DNA repair contribute to the pathogenesis of lamin-related diseases.