Laminin antibody

Laminins, a family of extracellular matrix glycoproteins, are the major noncollagenous constituent of basement membranes. They have been implicated in a wide variety of biological processes including cell adhesion, differentiation, migration, signaling, neurite outgrowth and metastasis. Laminins, composed of 3 non identical chains: laminin alpha, beta and gamma (formerly A, B1, and B2, respectively), have a cruciform structure consisting of 3 short arms, each formed by a different chain, and a long arm composed of all 3 chains. Each laminin chain is a multidomain protein encoded by a distinct gene. Several isoforms of each chain have been described. Different alpha, beta and gamma chain isomers combine to give rise to different heterotrimeric laminin isoforms which are designated by Arabic numerals in the order of their discovery, i.e. alpha1beta1gamma1 heterotrimer is laminin 1. The biological functions of the different chains and trimer molecules are largely unknown, but some of the chains have been shown to differ with respect to their tissue distribution, presumably reflecting diverse functions in vivo. This gene encodes the gamma chain isoform laminin, gamma 2. The gamma 2 chain, formerly thought to be a truncated version of beta chain (B2t), is highly homologous to the gamma 1 chain; however, it lacks domain VI, and domains V, IV and III are shorter. It is expressed in several fetal tissues but differently from gamma 1, and is specifically localized to epithelial cells in skin, lung and kidney. The gamma 2 chain together with alpha 3 and beta 3 chains constitute laminin 5 (earlier known as kalinin), which is an integral part of the anchoring filaments that connect epithelial cells to the underlying basement membrane. The epithelium-specific expression of the gamma 2 chain implied its role as an epithelium attachment molecule, and mutations in this gene have been associated with junctional epidermolysis bullosa, a skin disease characterized by blisters due to disruption of the epidermal-dermal junction. Two transcript variants resulting from alternative splicing of the 3' terminal exon, and encoding different isoforms of gamma 2 chain, have been described. The two variants are differentially expressed in embryonic tissues, however, the biological significance of the two forms is not known. Transcript variants utilizing alternative polyA_signal have also been noted in literature. [provided by RefSeq, Aug 2011]

LAMC2: 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. Ladsin exerts cell- scattering activity toward a wide variety of cells, including epithelial, endothelial, and fibroblastic cells. Defects in LAMC2 are a cause of epidermolysis bullosa junctional Herlitz type (H-JEB); also known as junctional epidermolysis bullosa Herlitz-Pearson type. JEB defines a group of blistering skin diseases characterized by tissue separation which occurs within the dermo-epidermal basement membrane. H-JEB is a severe, infantile and lethal form. Death occurs usually within the first six months of life. Occasionally, children survive to teens. H-JEB is marked by bullous lesions at birth and extensive denudation of skin and mucous membranes that may be hemorrhagic. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Secreted; Secreted, signal peptide; Extracellular matrix; Motility/polarity/chemotaxis

Chromosomal Location of Human Ortholog: 1q25-q31

Cellular Component: extracellular space; laminin-5 complex; laminin-2 complex; membrane; perinuclear region of cytoplasm; extracellular region; cell cortex

Molecular Function: heparin binding

Biological Process: extracellular matrix disassembly; epidermis development; extracellular matrix organization and biogenesis; hemidesmosome assembly; cell adhesion

Disease: Epidermolysis Bullosa, Junctional, Non-herlitz Type; Epidermolysis Bullosa, Junctional, Herlitz Type