Dynamics of nuclear lamina assembly and disassembly.

Abstract

What can be concluded about lamin dynamics? a. While the nuclear lamina forms a tight network of proteins, individual lamina members, such as the lamin C proteins, are only partially bound to the lamina. b. A prominent pool of nucleoplasmic lamins exists in most cells, which interacts with intranuclear structures (DNA? Histones? Replication and/or transcription complexes?) in a dynamic fashion. c. During mitosis lamins do not play a key role in the initial reformation of the nuclear envelope. However, they are important for the correct functioning of the nucleus immediately after mitosis. Many questions remain unanswered, although nuclear lamins have been studied at different levels for over 20 years. We have only just begun to understand their crucial role in several cellular processes. Some of the important questions that still remain are: a. The function of intranuclear lamin foci. Are these native nuclear structures (nuclear channels/tubules) and do they play a role in replication and transcription? b. The function of the nucleoplasmic veil of lamins. Are these molecules only temporarily bound to intranuclear structures as a result of affinity to chromosomes or nuclear proteins, or is there a functional interaction with these molecules? c. The extent to which lamin molecules add to nuclear membrane organisation. Do these molecules play a key role in keeping the membrane intact and the nucleus functional, or are they only one of many supportive component of the nuclear membrane?