To be or not be (in the LAD): emerging roles of lamin proteins in transcriptional regulation

Lamins are components of the nuclear lamina, a protein meshwork that underlies the nuclear membrane. Lamins interact with chromatin in transcriptionally silent regions defined as lamina-associated-domains (LADs). However, recent studies have shown that lamins regulate active transcription inside LADs. In addition, ChIP-seq analysis has shown that lamins interact with lamin-dependent promoters and enhancers located in the interior of the nucleus. Moreover, functional studies suggest that lamins regulate transcription at associated-promoters and long-range chromatin interactions of key developmental gene programs. This review will discuss emerging, non-canonical functions of lamins in controlling non-silent genes located both inside and outside of LADs, focusing on transcriptional regulation and chromatin organization in Drosophila and mammals as metazoan model organisms.

Automated summary

Lamins are components of the nuclear lamina and play a role in transcriptional regulation and chromatin organization. Recent studies have shown that lamins not only regulate gene transcription in regions associated with the nuclear lamina, but also interact with promoters and enhancers located inside the nucleus. Functional studies suggest that lamins play a role in transcription and chromatin interactions of key developmental gene programs. This review focuses on the emerging non-canonical functions of lamins in Drosophila and mammals as model organisms.