Laminin subunit alpha-2 explained

Laminin subunit alpha-2 is a protein that in humans is encoded by the LAMA2 gene.^{[1] [2] [3]}

Function

Laminin, an extracellular matrix protein, is a major component of the basement membrane. It is thought to mediate the attachment, migration, and organization of cells into tissues during embryonic development by interacting with other extracellular matrix components. It is composed of three subunits, alpha, beta, and gamma, which are bound to each other by disulfide bonds into a cross-shaped molecule. This gene encodes the alpha 2 chain, which constitutes one of the subunits of laminin 2 (merosin) and laminin 4 (s-merosin). Mutations in this gene have been identified as the cause of congenital merosin-deficient muscular dystrophy. Two transcript variants encoding different proteins have been found for this gene.

Further reading

• Timpl R . Macromolecular organization of basement membranes . Curr. Opin. Cell Biol. . 8 . 5 . 618–24 . 1997 . 8939648 . 10.1016/S0955-0674(96)80102-5 .
• Belkin AM, Stepp MA . Integrins as receptors for laminins . Microsc. Res. Tech. . 51 . 3 . 280–301 . 2000 . 11054877 . 10.1002/1097-0029(20001101)51:3<280::AID-JEMT7>3.0.CO;2-O . 45941383 .
• Jones KJ, Morgan G, Johnston H, etal . The expanding phenotype of laminin α2 chain (merosin) abnormalities: case series and review . J. Med. Genet. . 38 . 10 . 649–57 . 2002 . 11584042 . 10.1136/jmg.38.10.649 . 1734735 .
• Hori H, Kanamori T, Mizuta T, etal . Human laminin M chain: epitope analysis of its monoclonal antibodies by immunoscreening of cDNA clones and tissue expression . J. Biochem. . 116 . 6 . 1212–9 . 1995 . 7535762 . 10.1093/oxfordjournals.jbchem.a124666. immunoscreening .
• Helbling-Leclerc A, Zhang X, Topaloglu H, etal . Mutations in the laminin alpha 2-chain gene (LAMA2) cause merosin-deficient congenital muscular dystrophy . Nat. Genet. . 11 . 2 . 216–8 . 1995 . 7550355 . 10.1038/ng1095-216 . 34969060 .
• Yamada H, Shimizu T, Tanaka T, etal . Dystroglycan is a binding protein of laminin and merosin in peripheral nerve . FEBS Lett. . 352 . 1 . 49–53 . 1994 . 7925941 . 10.1016/0014-5793(94)00917-1 . 17529055 .
• Bonaldo MF, Lennon G, Soares MB . Normalization and subtraction: two approaches to facilitate gene discovery . Genome Res. . 6 . 9 . 791–806 . 1997 . 8889548 . 10.1101/gr.6.9.791 . free .
• Zhang X, Vuolteenaho R, Tryggvason K . Structure of the human laminin alpha2-chain gene (LAMA2), which is affected in congenital muscular dystrophy . J. Biol. Chem. . 271 . 44 . 27664–9 . 1996 . 8910357 . 10.1074/jbc.271.44.27664 . free .
• Squarzoni S, Villanova M, Sabatelli P, etal . Intracellular detection of laminin alpha 2 chain in skin by electron microscopy immunocytochemistry: comparison between normal and laminin alpha 2 chain deficient subjects . Neuromuscul. Disord. . 7 . 2 . 91–8 . 1997 . 9131649 . 10.1016/S0960-8966(96)00420-8 . 140209385 .
• Allamand V, Sunada Y, Salih MA, etal . Mild congenital muscular dystrophy in two patients with an internally deleted laminin alpha2-chain . Hum. Mol. Genet. . 6 . 5 . 747–52 . 1997 . 9158149 . 10.1093/hmg/6.5.747 . free .
• Durkin ME, Loechel F, Mattei MG, etal . Tissue-specific expression of the human laminin alpha5-chain, and mapping of the gene to human chromosome 20q13.2-13.3 and to distal mouse chromosome 2 near the locus for the ragged (Ra) mutation . FEBS Lett. . 411 . 2–3 . 296–300 . 1997 . 9271224 . 10.1016/S0014-5793(97)00686-8 . 45286880 . free .
• Mrowiec T, Melchar C, Górski A . HIV-protein-mediated alterations in T cell interactions with the extracellular matrix proteins and endothelium . Arch. Immunol. Ther. Exp. (Warsz.) . 45 . 2–3 . 255–9 . 1998 . 9597096 .
• Koch M, Olson PF, Albus A, etal . Characterization and Expression of the Laminin γ3 Chain: A Novel, Non-Basement Membrane–associated, Laminin Chain . J. Cell Biol. . 145 . 3 . 605–18 . 1999 . 10225960 . 10.1083/jcb.145.3.605 . 2185082 .
• Kuang W, Xu H, Vilquin JT, Engvall E . Activation of the lama2 gene in muscle regeneration: abortive regeneration in laminin alpha2-deficiency . Lab. Invest. . 79 . 12 . 1601–13 . 2000 . 10616210 .
• Pegoraro E, Fanin M, Trevisan CP, etal . A novel laminin alpha2 isoform in severe laminin alpha2 deficient congenital muscular dystrophy . Neurology . 55 . 8 . 1128–34 . 2000 . 11071490 . 10.1212/wnl.55.8.1128. 80274277 .
• McArthur CP, Wang Y, Heruth D, Gustafson S . Amplification of extracellular matrix and oncogenes in tat-transfected human salivary gland cell lines with expression of laminin, fibronectin, collagens I, III, IV, c-myc and p53 . Arch. Oral Biol. . 46 . 6 . 545–55 . 2001 . 11311202 . 10.1016/S0003-9969(01)00014-0 .

External links

• GeneReviews/NCBI/NIH/UW entry on Congenital Muscular Dystrophy Overview
• LOVD mutation database: LAMA2

Notes and References

1. Ehrig K, Leivo I, Argraves WS, Ruoslahti E, Engvall E . Merosin, a tissue-specific basement membrane protein, is a laminin-like protein . Proc Natl Acad Sci U S A . 87 . 9 . 3264–8 . Jun 1990 . 2185464 . 53880 . 10.1073/pnas.87.9.3264 . 1990PNAS...87.3264E . free .
2. Vuolteenaho R, Nissinen M, Sainio K, Byers M, Eddy R, Hirvonen H, Shows TB, Sariola H, Engvall E, Tryggvason K . Human laminin M chain (merosin): complete primary structure, chromosomal assignment, and expression of the M and A chain in human fetal tissues . J Cell Biol . 124 . 3 . 381–94 . Feb 1994 . 8294519 . 2119934 . 10.1083/jcb.124.3.381 .
3. Web site: Entrez Gene: LAMA2 laminin, alpha 2 (merosin, congenital muscular dystrophy).