Laminin subunit gamma-3 explained

Laminin subunit gamma-3 also known as LAMC3 is a protein that in humans is encoded by the LAMC3 gene.^{[1] [2]}

Function

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 are composed of 3 non identical chains: laminin alpha, beta and gamma (formerly A, B1, and B2, respectively) and they form 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 3. The gamma 3 chain is most similar to the gamma 1 chain, and contains all the 6 domains expected of the gamma chain. It is a component of laminin 12. The gamma 3 chain is broadly expressed in skin, heart, lung, and the reproductive tracts. In skin, it is seen within the basement membrane of the dermoepidermal junction at points of nerve penetration. However, it was also found that the gamma 3 is a prominent element of the apical surface of ciliated epithelial cells of lung, oviduct, epididymis, ductus deferens, and seminiferous tubules. The distribution of gamma 3-containing laminins along ciliated epithelial surfaces suggests that the apical laminins are important in the morphogenesis and structural stability of the ciliated processes of these cells.^[2]

A recent study found that LAMC3 plays a critical role in forming the convolution of the cerebral cortex. Particularly LAMC3 is expressed during the embryonic period, which contributes the formation of dendrites.^[3]

Further reading

• Tsuji T, Kawada Y, Kai-Murozono M, etal . Regulation of melanoma cell migration and invasion by laminin-5 and alpha3beta1 integrin (VLA-3) . Clin. Exp. Metastasis . 19 . 2 . 127–34 . 2002 . 11964076 . 10.1023/A:1014573204062 . 26714255 .
• Ido H, Ito S, Taniguchi Y, etal . Laminin Isoforms Containing the γ3 Chain Are Unable to Bind to Integrins due to the Absence of the Glutamic Acid Residue Conserved in the C-terminal Regions of the γ1 and γ2 Chains . J. Biol. Chem. . 283 . 42 . 28149–57 . 2008 . 18697739 . 10.1074/jbc.M803553200 . 2661386 . free .
• Otsuki T, Ota T, Nishikawa T, etal . Signal sequence and keyword trap in silico for selection of full-length human cDNAs encoding secretion or membrane proteins from oligo-capped cDNA libraries . DNA Res. . 12 . 2 . 117–26 . 2005 . 16303743 . 10.1093/dnares/12.2.117 . free .
• Burgeson RE, Chiquet M, Deutzmann R, etal . A new nomenclature for the laminins . Matrix Biol. . 14 . 3 . 209–11 . 1994 . 7921537 . 10.1016/0945-053X(94)90184-8 .
• Wilhelmsen K, Litjens SH, Sonnenberg A . Multiple Functions of the Integrin α6β4 in Epidermal Homeostasis and Tumorigenesis . Mol. Cell. Biol. . 26 . 8 . 2877–86 . 2006 . 16581764 . 10.1128/MCB.26.8.2877-2886.2006 . 1446957 .
• Orian-Rousseau V, Aberdam D, Rousselle P, etal . Human colonic cancer cells synthesize and adhere to laminin-5. Their adhesion to laminin-5 involves multiple receptors among which is integrin alpha2beta1 . J. Cell Sci. . 111 . 14. 1993–2004 . 1998 . 10.1242/jcs.111.14.1993 . 9645947 .
• Cserhalmi-Friedman PB, Olson PF, Koch M, etal . Structural analysis and mutation detection strategy for the human LAMC3 gene . Biochem. Biophys. Res. Commun. . 280 . 1 . 39–44 . 2001 . 11162474 . 10.1006/bbrc.2000.4086 .
• 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 .

Notes and References

1. Koch M, Olson PF, Albus A, Jin W, Hunter DD, Brunken WJ, Burgeson RE, Champliaud MF . Characterization and Expression of the Laminin γ3 Chain: A Novel, Non-Basement Membrane–associated, Laminin Chain . J. Cell Biol. . 145 . 3 . 605–18 . May 1999 . 10225960 . 2185082 . 10.1083/jcb.145.3.605.
2. Web site: Entrez Gene: LAMC3 Laminin, gamma 3 .
3. Nature Genetics 2011; DOI: 10.1038/ng.836