Cargando…

Laminin–sulfatide binding initiates basement membrane assembly and enables receptor signaling in Schwann cells and fibroblasts

Endoneurial laminins (Lms), β1-integrins, and dystroglycan (DG) are important for Schwann cell (SC) ensheathment and myelination of axons. We now show that SC expression of galactosyl-sulfatide, a Lm-binding glycolipid, precedes that of Lms in developing nerves. This glycolipid anchors Lm-1 and -2 t...

Descripción completa

Detalles Bibliográficos
Autores principales: Li, Shaohua, Liquari, Patricia, McKee, Karen K., Harrison, David, Patel, Raj, Lee, Sean, Yurchenco, Peter D.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2005
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2171891/
https://www.ncbi.nlm.nih.gov/pubmed/15824137
http://dx.doi.org/10.1083/jcb.200501098
Descripción
Sumario:Endoneurial laminins (Lms), β1-integrins, and dystroglycan (DG) are important for Schwann cell (SC) ensheathment and myelination of axons. We now show that SC expression of galactosyl-sulfatide, a Lm-binding glycolipid, precedes that of Lms in developing nerves. This glycolipid anchors Lm-1 and -2 to SC surfaces by binding to their LG domains and enables basement membrane (BM) assembly. Revealingly, non–BM-forming fibroblasts become competent for BM assembly when sulfatides are intercalated into their cell surfaces. Assembly is characterized by coalescence of sulfatide, DG, and c-Src into a Lm-associated complex; by DG-dependent recruitment of utrophin and Src activation; and by integrin-dependent focal adhesion kinase phosphorylation. Collectively, our findings suggest that sulfated glycolipids are key Lm anchors that determine which cell surfaces can assemble Lms to initiate BM assembly and DG- and integrin-mediated signaling.