Laminin is a major component of the basement membrane. This 900 kDa glycoprotein is composed of three sub-units. Laminin attaches to components of the basement membrane (collagen IV, heparan sulphate proteoglycan) or to receptors on cell surfaces (integrin).
Laminin causes neurite growth, has an effect on migration, growth, morphology and the attachment of Schwann cells and olfactory neurons, and is involved in tissue repair.
It also regulates the growth of a large number of cell types including macrophages, hepatocytes, keratinocytes, melanocytes, myocardiocytes, cells transformed by Ras, haematopoietic stem cells.
Furthermore, laminin has an effect on human neutrophils (oxydating mechanisms), suppresses lymphocyte responses to T cell mitogens, plays a role in polarising epithelial cells and can be used to study tumourous invasion.