laminaassosierte

Lamina-associated (German: laminaassozierte) refers to chromatin regions and other nuclear components that interact with the nuclear lamina, a fibrous network lining the inner nuclear envelope. The lamina is built mainly from lamin proteins (lamin A/C and lamin B) and a set of associated membrane proteins, such as LBR, Emerin, and LAP2, which together contribute to the structural organization of the genome in three dimensions.

A prominent example of lamina-associated chromatin is the lamina-associated domain, or LAD. LADs are large genomic regions that physically contact the nuclear lamina. They are typically gene-poor, late-replicating, and enriched for heterochromatic histone marks, reflecting a repressive chromatin state. LADs tend to lie at the nuclear periphery and are associated with reduced transcription, although gene activity can occur in specific developmental or cellular contexts. The set of LADs can vary between cell types and during differentiation.

Functionally, the lamina helps organize the genome into distinct compartments, contributing to global gene regulation by separating active interior chromatin from repressed peripheral chromatin. Lamina–chromatin interactions are dynamic and can change during development, differentiation, and aging. Disruptions to lamina–chromatin contacts are linked to aging phenotypes and muscular dystrophies known as laminopathies, underscoring the role of lamina-associated organization in cellular identity and health.

Common methods to map lamina-associated regions include DamID, which fuses a DNA adenine methyltransferase to lamins, and Lamin A/C or Lamin B1 chromatin immunoprecipitation followed by sequencing, with newer approaches continuing to refine resolution and accuracy.