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PROSITE documentation PDOC50025

Laminin G domain profile





Description

The Laminin G or LNS domain (for Laminin-α, Neurexin and Sex hormone-binding globulin) is an around 180 amino acid long domain found in a large and diverse set of extracellular proteins [1,2]. It often occures in multiple copies probably serving as general protein interaction domains that bind the target proteins and other macromolecules, such as carbohydrates. In most proteins, the precise function of the laminin G domain is unknown. A large number of ligands in the G domain of laminin has been reported, including heparin, sulfatides, integrins, dystroglycan, nidogen, and fibulin [3,4,5]. In neurexin the G domain is known to bind neurexophilins, α-latrotoxin and neuroligins.

The crystal structure of Laminin G domain of neurexin 1-β has been solved [6]. It is composed of 14 β strands and one α helix. The 14 strands form two antiparallel seven stranded β sheets in a jelly roll fold. The α helix is located between β strand 12 and 13. The structure of the laminin G domain is similar to the lectin domain. Alignment of various LNS with neurexin 1-β reveal that only the central part (between strand 4 and 13) is conserved.

Some proteins known to contain a laminin G domain are listed below:

  • Eukaryotic laminin α chains. It is a major noncollagenous components of basement membranes that mediate cell adhesion, growth migration, and differentiation.
  • Mammalian neurexins.
  • Sex steroid binding protein SBP/SHBG. It regulates the plasma metabolic clearance rate of steroid hormones by controlling their plasma concentration.
  • Agrin, a basal lamina protein. It causes the aggregation of acetylcholine receptors on cultured muscle fibers.
  • Vitamin K dependent protein S. An anticoagulant plasma protein that acts as a cofactor to activated protein C in the degradation of coagulation factors VA and VIIIA. It helps to prevent coagulation and stimulating fibrinolysis.
  • Drosophila slit protein, essential for development of midline glia and commissural axon pathways. It is composed of four leucine-rich repeats, seven EGF-like domains, a laminin G-like repeat and the CTCK.

The profile we developed covers the whole domain, including the highly divergent ends. We artificially placed the threshold at 12.1 to remove matches against thrombospondin-like N-terminal domain, a structurally homologue module. Thus we also remove few real matches which have a score between 8.5 and 12.1.

Last update:

December 2001 / First entry.

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Technical section

PROSITE method (with tools and information) covered by this documentation:

LAM_G_DOMAIN, PS50025; Laminin G domain profile  (MATRIX)


References

1AuthorsVuolteenaho R. Chow L.T. Tryggvason K.
TitleStructure of the human laminin B1 chain gene.
SourceJ. Biol. Chem. 265:15611-15616(1990).
PubMed ID1975589

2AuthorsBeckmann G. Hanke J. Bork P. Reich J.G.
TitleMerging extracellular domains: fold prediction for laminin G-like and amino-terminal thrombospondin-like modules based on homology to pentraxins.
SourceJ. Mol. Biol. 275:725-730(1998).
PubMed ID9480764

3AuthorsYurchenco P.D. Sung U. Ward M.D. Yamada Y. O'Rear J.J.
TitleRecombinant laminin G domain mediates myoblast adhesion and heparin binding.
SourceJ. Biol. Chem. 268:8356-8365(1993).
PubMed ID8463343

4AuthorsSung U. O'Rear J.J. Yurchenco P.D.
TitleLocalization of heparin binding activity in recombinant laminin G domain.
SourceEur. J. Biochem. 250:138-143(1997).
PubMed ID9432001

5AuthorsTalts J.F. Andac Z. Gohring W. Brancaccio A. Timpl R.
TitleBinding of the G domains of laminin alpha1 and alpha2 chains and perlecan to heparin, sulfatides, alpha-dystroglycan and several extracellular matrix proteins.
SourceEMBO J. 18:863-870(1999).
PubMed ID10022829
DOI10.1093/emboj/18.4.863

6AuthorsRudenko G. Nguyen T. Chelliah Y. Sudhof T.C. Deisenhofer J.
TitleThe structure of the ligand-binding domain of neurexin Ibeta: regulation of LNS domain function by alternative splicing.
SourceCell 99:93-101(1999).
PubMed ID10520997



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