The Nuclear Lamina: Molecular Organization and Interaction with Chromatin

The nuclear lamina is located between the inner nuclear membrane and the peripheral chromatin. It is composed mainly of nuclear lamins and lamina-associated proteins. The nuclear lamina is involved in nuclear organization, cell cycle regulation, and differentiation. As such, impairment in its architecture and/or function leads to genetic diseases and apoptosis. This article describes the molecular organization of the nuclear lamins, their assembly into filaments, their distribution within the nucleus, and the complex network of interactions between them and other proteins of the inner nuclear membrane. Recent findings unraveled evidence for specific interactions between proteins of the nuclear lamina and the chromatin. These include interactions between nuclear lamins and core histones, Lamina Associated Polypeptide 2 (LAP2), and the Barrier to Autointegration Factor (BAF) and interactions between lamin B receptor (LBR) and the chromodomain protein HP1. Taken together, these studies attribute a role for both the nuclear lamins and the lamina-associated proteins, LAP2 and LBR, in nuclear organization and nuclear assembly.