Accession number: PF04916 Laminin A (alpha-chain)

Description

Basement membranes separate dissimilar cell types and thus compartmentalize almost all tissues. They are thin sheets of extracellular matrix whose main components are type IV collagen, nidogen, sulphated proteoglycans, and laminins. Laminins are found in all basement membranes, but also in embryonic mesenchyme and loose connective tissue. Lamin is thought to mediate the attachment, migration and organisation of cells into tissues during embryonic development by interacting with other extracellular matrix components.

All native laminins identified so far are composed of one alpha, one beta, and one gamma chain and 12 different heterotrimers have been proposed based on five alpha, three beta, and three gamma chains. In vitro studies have indicated that laminins mediate a variety of biological functions. First they form a self-assembling structural network to which other components of the basement membrane attach. Second, they attach cells to the extracellular matrix via alpha-dystroglycan and integrin receptors. Third, they convey information to the cell interior via these receptors, as exemplified by mesenchymal to epithelial transitions in kidney, myogenesis in skeletal muscle, and outgrowth of neurites. Studies of mutated genes as well as gene targeting experiments have indicated different functional roles for the different laminins.

This family of proteins represents the alpha chain of laminin.

Description text from InterPro entry IPR007000