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© The Rockefeller University Press,
0021-9525/2001//835 $5.00
The Journal of Cell Biology, Volume 153, Number 4,
, 2001 835-850
Original Article |
The Short Arm of the Laminin
2 Chain Plays a Pivotal Role in the Incorporation of Laminin 5 into the Extracellular Matrix and in Cell Adhesion
meneguzz{at}unice.fr
Laminin 5 is a basement membrane component that actively promotes adhesion and migration of epithelial cells. Laminin 5 undergoes extracellular proteolysis of the
2 chain that removes the NH2-terminal short arm of the polypeptide and reduces the size of laminin 5 from 440 to 400 kD. The functional consequence of this event remains obscure, although lines of evidence indicate that cleavage of the
2 chain potently stimulated scattering and migration of keratinocytes and cancer cells. To define the biological role of the
2 chain short arm, we expressed mutated
2 cDNAs into immortalized
2-null keratinocytes. By immunofluorescence and immunohistochemical studies, cell detachment, and adhesion assays, we found that the
2 short arm drives deposition of laminin 5 into the extracellular matrix (ECM) and sustains cell adhesion. Our results demonstrate that the unprocessed 440-kD form of laminin 5 is a biologically active adhesion ligand, and that the
2 globular domain IV is involved in intermolecular interactions that mediate integration of laminin 5 in the ECM and cell attachment.
Key Words: keratinocyte epithelial adhesion cell migration basement membrane epidermolysis bullosa
© 2001 The Rockefeller University Press
Abbreviations used in this paper: ECM, extracellular matrix; HA, hemagglutinin; JEB, junctional epidermolysis bullosa; MMP, matrix metalloprotease; pAb, polyclonal antibody.
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