Domains of laminin with growth-factor activity.
Laminin and fragments (1, 1-4) containing the inner rod-like segments from its short arms, which consist of cysteine-rich, "EGF-like" repeats, stimulated thymidine incorporation in cultured cells possessing EGF receptors but had no effect on a cell line lacking this receptor. The response was comparable to that of EGF concerning effective concentrations, magnitude, time dependence, and synergistic enhancement by insulin. Other fragments (4 and 8) were inactive. Laminin and its active fragments could not compete with the binding of EGF to cells. There was no correlation between growth promotion and attachment of cells to a high affinity binding site present on laminin fragment 8. The data indicate that mitogenic effects induced by laminin and EGF proceed in some steps via related pathways and that different domains of laminin are involved in growth promotion and in adhesion and spreading of cells.
Panayotou
G
G
National Institute for Medical Research, London, England.
End
P
P
Aumailley
M
M
Timpl
R
R
Engel
J
J
D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured / Q000166:cytology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005109:Extracellular Matrix / Q000502:physiology; D006133:Growth Substances / Q000502:physiology*; D007797:Laminin / Q000502:physiology* / Q000648:ultrastructure; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000494:pharmacology; D051379:Mice; D010446:Peptide Fragments / Q000494:pharmacology; D012995:Solubility; D013329:Structure-Activity Relationship; D013997:Time Factors
D006133:Growth Substances; D007797:Laminin; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D010446:Peptide Fragments; C029967:nidogen; D004815:Epidermal Growth Factor