Nuclear lamins and chromatin: When structure meets function

In our model we propose that lamins are major components of a nuclear scaffold which is essential for various nuclear processes such as transcription, DNA replication, chromatin organization and DNA repair (Dechat et al., 2008; Goldman et al., 2002). We further speculate that this lamin based scaffold provides a docking site and organizing center for chromatin and the multicomponent complexes involved in chromatin regulation. Alterations in such a scaffold caused either by changes in lamin expression patterns or by the expression of disease causing mutant lamins can result in the misregulation of nuclear functions leading, for example, to defects in cell cycle progression and differentiation (Dechat et al., 2008). In support of this two recent studies show that adult stem cell differentiation is impaired in HGPS and in premature-aging mice (Espada et al., 2008; Scaffidi and Misteli, 2008).