Laminin 332 Research Paper

Laminin 332

Laminin 332 is present in the BMZ of nearly all epithelial tissues in the human body [140]. Furthermore, laminin 332 is the main component found at the upper lamina densa/lamina lucida border at the base of the anchoring filaments [120]. Mutations in laminin 332 are linked to a condition that causes skin fragility and severe blistering, which is known as junctional epidermolysis bullosa [141-143]. Moreover, the absence of laminin 332 expression considerably disrupts the epidermal adhesion, as seen in patients having the lethal disease known as Herlitz junctional epidermolysis bullosa [107, 141].

Laminin 332 can bind via the G domain to α6β4 and α3β1 integrins [144, 145]. It also has binding sites along its β-chain for laminin 311 and collagen VII [146], and other binding sites along the γ-chain for perlecan and different types of collagen (IV, VII, and XVII) [144, 146]. Several studies showed that laminin 332 is involved in various cellular processes, such as epithelial cell adhesion, spreading and migration [147, 148]. The

The core protein includes three G domains: the G1 (N-terminal), G2, and G3 (C-terminal), which are separated by two rod-like segments. Genes encode for two kinds of nidogens with a similar structural organization: nidogen-1 (30 nm long) and nidogen-2 (40 nm long). Nidogen has various binding sites for laminins, perlecan, fibrinogen, fibronectin and collagen IV [118, 152]. The nidogen binds to collagen type IV via the G2 domain, while the G3 domain has a high affinity to laminin Y1 chain [153, 154]. Interestingly, the nidogen-laminin binding has been recognized as one of the highest binding affinities in nature [155]. However, the absence of both nidogen-1 and nidogen-2 does not disrupt the formation of a functional BMZ [103, 107,