Nuclear lamina

Nuclear lamina is a dense fibrillar network inside the nucleus of a eukaryotic cell. It is composed of intermediate filaments and membrane associated proteins. The nuclear lamina is involved in many different aspects of nuclear function, including DNA replication, cell division, nuclear size and shape, and the organization and regulation of chromatin.

Structure

The nuclear lamina is a dense network of proteins located on the inner side of the nuclear envelope. It is composed of lamins, which are type V intermediate filaments. Lamins are divided into A-type and B-type, based on their biochemical properties and expression patterns. A-type lamins include lamin A and lamin C, which are produced by alternative splicing of the LMNA gene. B-type lamins include lamin B1 and lamin B2, which are encoded by the LMNB1 and LMNB2 genes, respectively.

Function

The nuclear lamina is involved in many different aspects of nuclear function. It provides mechanical support to the nucleus and helps to maintain its size and shape. It is also involved in the organization and regulation of chromatin, and plays a role in DNA replication and cell division. Mutations in the genes encoding lamins can lead to a variety of diseases, collectively known as laminopathies, which include muscular dystrophy, cardiomyopathy, and premature aging syndromes.

Laminopathies

Laminopathies are a group of rare genetic disorders caused by mutations in the genes encoding lamins. They include a wide range of diseases, from muscular dystrophy and cardiomyopathy to premature aging syndromes. The most common laminopathy is Hutchinson-Gilford progeria syndrome, a condition characterized by rapid aging that begins in childhood. Other laminopathies include Emery-Dreifuss muscular dystrophy, familial partial lipodystrophy, and restrictive dermopathy.

See also

• Nuclear envelope
• Intermediate filament
• Lamin
• Laminopathies

• 
  Laminopathic nuclei
• Structure and function of the nuclear lamina
  Structure and function of the nuclear lamina