kernlamina

Kernlamina, also known as the nuclear lamina, is a dense, fibrous network that lies just beneath the inner nuclear membrane in most eukaryotic cells. It provides mechanical support to the nucleus, helps maintain its shape, and acts as a scaffold for organizing chromatin and regulating gene expression.

The lamina is primarily composed of lamins, a family of intermediate filament proteins. In humans, there are A-type lamins (lamin A and lamin C, encoded by LMNA) and B-type lamins (lamin B1 and B2, encoded by LMNB1 and LMNB2). The lamina associates with a range of lamin-associated proteins, including emerin, LAP2 family members, MAN1, LBR, and LINC complex components such as nesprins and SUN proteins, which connect the lamina to the cytoskeleton.

Functions of the kernlamina include providing structural integrity to the nucleus, organizing and anchoring chromatin to influence gene expression through lamina-associated domains (LADs), participating in DNA replication and repair, and contributing to mechanotransduction and nuclear movement during cell migration. The lamina is dynamic and reorganizes during the cell cycle, disassembling as the nuclear envelope breaks down in mitosis and reassembling during telophase and reformation of the envelope.

Mutations and defects in lamins or associated proteins give rise to a group of disorders known as laminopathies. These can affect muscle, adipose tissue, the cardiac system, and lead to premature aging syndromes in some cases. Because of its central roles in structure and regulation, the kernlamina is a key focus in studies of nuclear organization and disease.