Biologically Active Sequences in the Mouse Laminin α3 Chain G Domain
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- 作者：Shunsuke Urushibata ; Fumihiko Katagiri ; Shu Takaki ; Yuji Yamada ; Chikara Fujimori ; Kentaro Hozumi ; Yamato Kikkawa ; Yuichi Kadoya ; Motoyoshi Nomizu
- 刊名：Biochemistry
- 出版年：2009
- 出版时间：November 10, 2009
- 年：2009
- 卷：48
- 期：44
- 页码：10522-10532
- 全文大小：1053K
- 年卷期：v.48,no.44(November 10, 2009)
- ISSN：1520-4995
文摘
The laminin α3 chain is mainly expressed at the skin, and its C-terminal G domain has a critical role in multiple biological functions. We screened for biologically active sites on the mouse laminin α3 chain G domain using 107 synthetic peptides on coated plates and conjugated to Sepharose beads with HT1080 human fibrosarcoma cells, HaCaT human skin keratinocyte cells, and human dermal fibroblasts (HDFs). Eleven peptides exhibited cell attachment activity with respect to the peptide-coated plates and/or peptide−Sepharose beads. MA3G28 (WTIQTTVDRGLL) strongly binds to HaCaT cells. Four peptides promoted PC12 cell neurite outgrowth. Heparin inhibited attachment of HDFs to eight peptides on the coated plates. In contrast, EDTA significantly inhibited attachment of HDFs to MA3G27 (NAPFPKLSWTIQ) and MA3G28 but had no effect on the attachment of the other peptides. HDF cells formed well-organized actin stress fibers and focal contacts with vinculin accumulation on MA3G27. Additionally, attachment of HDFs to MA3G27 was inhibited by anti-α6 and anti-β1 integrin antibodies, suggesting that MA3G27 promotes α6β1 integrin-mediated cell adhesion. MA3G57 (NQRLASFSNAQQS) exhibited cell attachment activity only in the peptide bead assay. MA3G57 conjugated to a chitosan membrane promoted HDF attachment and spreading with well-organized actin stress fibers. The anti-β1 integrin antibody partially inhibited attachment of HDFs to the MA3G57−chitosan membrane, suggesting that the MA3G57 site is involved in β1 integrin-mediated cell attachment. These active sites are likely important in the biological activities of the laminin α3 chain G domain and would be useful for the study of molecular mechanisms of laminin−receptor interactions.