Laminin IV type B (IPR013015)

Short name: Laminin_IV_B

Overlapping homologous superfamilies


Domain relationships



Laminin is a large molecular weight glycoprotein present only in basement membranes in almost every animal tissue. Each laminin is a heterotrimer assembled from alpha, beta and gamma chain subunits, secreted and incorporated into cell-associated extracellular matrices. The laminins can self-assemble, bind to other matrix macromolecules, and have unique and shared cell interactions mediated by integrins, dystroglycan, and other receptors. Through these interactions, laminins critically contribute to cell differentiation, shape and movement, maintenance of tissue phenotypes, and promotion of tissue survival [PMID: 10842354, PMID: 15363809].

The different laminin chains share a 600-residue domain I/II which oligomerizes into a rod-like coiled-coil structure forming the long arm of laminins. The N-terminal short arms consist of rod-like elements (domain III and V) formed by tandem arrays of laminin-type EGF modules and several globular domains: domains IV and domain VI (laminin N-terminal). All alpha chains share a unique C-terminal G domain which consists of five laminin G modules [PMID: 3182802]. Laminin IV domain is also found in the perlecan protein, an integral component of basement membranes, which also serves as an attachment substrate for cells, but it is not found in short laminin chains (alpha4 or beta3). The function of this domain is not yet known.

The domain IV of laminin beta chains displays no sequence homology to other laminin IV domains. This entry represents this atypical domain IV.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles