The nuclear lamina is a network of intermediate filaments that resides just beneath the nuclear membrane in eukaryotic cells and provides strength and support for the nucleus. The nuclear lamina is also involved in processes such as cell cycle regulation, RNA transcription and DNA synthesis.
The nuclear lamina is made up of nuclear lamins which are intermediate filaments of the cytoskeleton. Intermediate filaments are coded by at least 65 genes and are made up of keratin monomers that are bound together at an extended central alpha-helical domain. These dimers thern align with other keratin dimers in an antiparallel fashion to form tetramers, giving them their strength. Intermediate filaments then form a mesh network just underneath the nuclear membrane and this is the nuclear lamina.
The nuclear lamina is also linked to cell cycle regulation as nuclear liamins can bind chromatin via their rod domains. However during mitosis the nuclear lamina is broken down during metaphase when the chromosomes begin to line up in the centre of the cell. At the end of mitosis there is a build up of essential cellular machinery that was broken down beforehand, this is where the nuclear lamina is made back up.
- ↑ Molecular Biology of the Cell, 5th Editon, Alberts et al, Garland Science, 2008.
- ↑ The Nuclear Lamina and its Functions in the Nucleus, Gruenbaum et al, pubmed.gov, 2003.
- ↑ Intermediate Filaments: from Cell Architecture to Nanomechanics, Herrman et al, Nature Reviews Molecular Cell Biology, 2007
- ↑ Breaking and Making of the Nuclear Envelope, Margalit et al, Journal of Cellular Biochemistry, 3rd Edition, 2005