Linkage of lamins to fidelity of gene transcription.

Two major events are emerging as being involved in the fine regulatory mechanisms that control gene expression through the nuclear envelope/lamina. The first is the linkage of envelope proteins to transcription factors, most of which function as transcriptional repressors. The second is the interplay between nuclear lamina/nuclear envelope proteins and chromatin, through more or less direct interactions with DNA-binding proteins. The first mechanism appears to play a major role in tissue-specific functions, whereas the latter mechanism likely modifies higher-order chromatin organization, thus regulating differentiation and aging. This review highlights the importance of the study of a group of genetic diseases, collectively referred to as laminopathies, to understand the actual role played by lamins in ensuring the fidelity of gene expression and in modulating cell differentiation.