Figure 19.

Nuclear lamins. (A) Schematic drawing of nuclear lamins and their nearby protein interactions. Nuclear lamins localizes underneath the inner nuclear membrane where they directly bind lamina-associated proteins (e.g., emerin, nesprin-1, and nesprin-2). Nesprin-1 and emerin both interact with nuclear actin and mediate the cortical actin cytoskeleton assembly at the nuclear envelope. The integral membrane protein MAN1 allows lamins to associate with transcription factors (e.g., SMAD), while SUN1/2 allows lamins to associate with microtubules and anchors nesprin-2 to the nuclear envelope. Interactions with barrier-to-autointegration factor (BAF) and lamin B receptor (LBR), as well as directly to chromatin, allows lamins to influence chromatin organization and gene expression. (B) Electron micrograph of the nuclear lamina composed of lamin intermediate filaments and associated proteins that extend between the nuclear pore complexes (NPCs). [Parts A and B modified, with permission, from (80).]