Bifunctional peptides derived from homologous loop regions in the laminin alpha chain LG4 modules interact with both alpha 2 beta 1 integrin and syndecan-2.
Laminin alpha chains show diverse biological functions in a chain-specific fashion. The laminin G-like modules (LG modules) of the laminin alpha chains consist of a 14-stranded beta-sheet sandwich structure with biologically active sequences found in the connecting loops. Previously, we reported that connecting loop regions between beta-strands E and F in the mouse laminin alpha chain LG4 modules exhibited chain-specific activities. In this study, we focus on the homologous loop regions in human laminin alpha chain LG4 modules using five synthetic peptides (hEF-1-hEF-5). These homologous peptides induced chain-specific cellular responses in various cell types. Next, to examine the dual-receptor recognition model, we synthesized chimeras (cEF13A-cEF13E) derived from peptides hEF-1 and hEF-3. All of the chimeric peptides promoted fibroblast attachment as well as the parental peptides. Attachment of fibroblasts to cEF13A and cEF13B was inhibited by anti-integrin alpha2 and beta1 antibodies and by heparin, while cell adhesion to cEF13C, cEF13D, and cEF13E was blocked only by heparin. Actin organization of fibroblasts on cEF13C was not different from that on hEF-3, but cEF13B induced membrane ruffling at the tips of the actin stress fibers. These results suggest that cEF13B had bifunctional effects on cellular behaviors through alpha2beta1 integrin and heparin/heparan sulfate proteoglycan. We conclude that the approach utilizing chimeric peptides is useful for examining cellular mechanisms in dual-receptor systems.
Yokoyama
Fumiharu
F
Graduate School of Environmental Earth Science, Hokkaido University, Sapporo 060-0810, Japan.
Suzuki
Nobuharu
N
Kadoya
Yuichi
Y
Utani
Atsushi
A
Nakatsuka
Hiroko
H
Nishi
Norio
N
Haruki
Masahiro
M
Kleinman
Hynda K
HK
Nomizu
Motoyoshi
M
D000199:Actins / Q000737:chemistry; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D019138:Antibodies, Blocking / Q000737:chemistry / Q000378:metabolism; D001666:Binding Sites, Antibody; D002448:Cell Adhesion; D002460:Cell Line; D045744:Cell Line, Tumor; D006493:Heparin / Q000737:chemistry; D006801:Humans; D038982:Integrin alpha2beta1 / Q000276:immunology / Q000378:metabolism*; D007797:Laminin / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000138:chemical synthesis / Q000378:metabolism*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011509:Proteoglycans / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000037:antagonists & inhibitors / Q000138:chemical synthesis / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D053669:Syndecan-2; D016596:Vinculin / Q000737:chemistry
D000199:Actins; D019138:Antibodies, Blocking; D038982:Integrin alpha2beta1; D007797:Laminin; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D011509:Proteoglycans; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; C508245:SDC2 protein, human; C508246:Sdc2 protein, mouse; D016596:Vinculin; D053669:Syndecan-2; C084098:laminin A; D006493:Heparin