Identification of a heparin binding site and the biological activities of the laminin α1 chain carboxy-terminal globular domain

✍ Scribed by Ichiro Yoshida; Ken-Ichiro Tashiro; Akira Monji; Isao Nagata; Yoshihito Hayashi; Yoshio Mitsuyama; Nobutada Tashiro

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 342 KB
• Volume: 179
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/(sici)1097-4652(199904)179:1<18::aid-jcp3>3.0.co;2-k

✦ Synopsis

The carboxy-terminal globular domain (G-domain) of the laminin ␣1 chain has been shown to promote heparin binding, cell adhesion, and neurite outgrowth. In this study, we defined the potential sequences originating from the G-domain of laminin ␣1 chain which possess these functional activities. A series of peptides were synthesized from the G-domain, termed LG peptides (LG-1 to LG-6) and were tested for their various biological activities. In the direct [ 3 H]heparin binding assays, LG-6 (residues 2,335-2,348: KDFLSIELVRGRVK) mediated high levels of [ 3 H]heparin binding, and this peptide also directly promoted cell adhesion and spreading, including B16F10, M2, HT1080, and PC12 cells. The peptide LG-6 also promoted the neurite outgrowth of PC12 cells, mouse granule cells, and chick telencephalic cells. An anti-peptide LG-6 antibody inhibited laminin-1 and peptide LG-6 -mediated cell adhesion and neurite outgrowth. Furthermore, an anti-integrin ␣2 antibody also inhibited the cell adhesion activity. These results suggest that peptide LG-6 plays a functional role as a heparin binding site in the G-domain of the laminin ␣1 chain, and this sequence was thus concluded to play a crucial role in regulating cell adhesion and spreading and neurite outgrowth which is related to integrin ␣2.