LAMA3

Domain

The alpha-helical domains I and II are thought to interact with other laminin chains to form a coiled coil structure.

Domain G is globular.

Function

Binding to cells via a high affinity receptor, laminin is thought to mediate the attachment, migration and organization of cells into tissues during embryonic development by interacting with other extracellular matrix components.

Laminin-5 is thought to be involved in (1) cell adhesion via integrin alpha-3/beta-1 in focal adhesion and integrin alpha-6/beta-4 in hemidesmosomes, (2) signal transduction via tyrosine phosphorylation of pp125-FAK and p80, (3) differentiation of keratinocytes.

Involvement in disease

Epidermolysis bullosa, junctional 2A, intermediate

JEB2A

A form of epidermolysis bullosa, a genodermatosis characterized by recurrent blistering, fragility of the skin and mucosal epithelia, and erosions caused by minor mechanical trauma. JEB2A is an autosomal recessive, intermediate form in which blistering lesions occur between the epidermis and the dermis at the lamina lucida level of the basement membrane zone. In intermediate forms of junctional epidermolysis bullosa, blistering does not lead to the formation of chronic granulation tissue and does not affect the lifespan of affected individuals. Nail dystrophy and dental enamel defects are present. Scarring or non-scarring alopecia and diffuse hair loss may occur.

None

The disease is caused by variants affecting the gene represented in this entry.

Epidermolysis bullosa, junctional 2B, severe

JEB2B

A form of epidermolysis bullosa, a genodermatosis characterized by recurrent blistering, fragility of the skin and mucosal epithelia, and erosions caused by minor mechanical trauma. JEB2B is an autosomal recessive form in which blistering lesions occur between the epidermis and the dermis at the lamina lucida level of the basement membrane zone. It belongs to the severe spectrum of junctional epidermolysis bullosa (previously known as generalized severe or Herlitz type), characterized by onset of blistering over large regions of the body at birth or in early infancy. Blistering also affects the mucous membranes, such as the moist lining of the mouth and digestive tract, which can make it difficult to eat and digest food. The extensive blistering leads to scarring and the formation of red, bumpy patches called granulation tissue. Other complications can include fusion of the fingers and toes, abnormalities of the fingernails and toenails, joint deformities, dental enamel defects, and alopecia. Severe, junctional forms are associated with death in the first 6 to 24 months of life.

None

The disease is caused by variants affecting the gene represented in this entry.

Epidermolysis bullosa, junctional 2C, laryngoonychocutaneous

JEB2C

A form of epidermolysis bullosa, a genodermatosis characterized by recurrent blistering, fragility of the skin and mucosal epithelia, and erosions caused by minor mechanical trauma. JEB2C is an autosomal recessive, severe form in which blistering lesions occur between the epidermis and the dermis at the lamina lucida level of the basement membrane zone. JEB2C manifestations appear in early infancy and include hoarse cry, skin ulceration, nail dystrophy with recurrent loss of toenails and fingernails, and conjunctival scarring. Some patients have amelogenesis imperfecta. Death in childhood is common.

None

The disease is caused by variants affecting the gene represented in this entry.

Tissue Specificity

Skin; respiratory, urinary, and digestive epithelia and in other specialized tissues with prominent secretory or protective functions. Epithelial basement membrane, and epithelial cell tongue that migrates into a wound bed. A differential and focal expression of the subunit alpha-3 is observed in the CNS.

Cellular localization

• Secreted
• Extracellular space
• Extracellular matrix
• Basement membrane
• Major component.

Alternative names

LAMNA, LAMA3, Laminin subunit alpha-3, Epiligrin 170 kDa subunit, Epiligrin subunit alpha, Kalinin subunit alpha, Laminin-5 subunit alpha, Laminin-6 subunit alpha, Laminin-7 subunit alpha, Nicein subunit alpha, E170

Database links

swissprot:Q16787 omim:150310 omim:226650 omim:226700 entrezGene:3918 entrezGene:3914 swissprot:Q13751 swissprot:Q13753 entrezGene:3909