Fibronectin is a binding partner for the myelin-associated glycoprotein (siglec-4a)

The myelin-associated glycoprotein (MAG) mediates cell-cell interactions be tween myelinating glial cells and neurons. Here we describe the extracellul ar matrix glycoprotein fibronectin as a binding partner of MAG. It has been identified by affinity precipitation with MAG-Fe from NG108-15 cells and b y microsequencing of two peptides derived from a 210-kDa protein band. West ern blot analysis showed that fibronectin is also present in;MAG binding pa rtners isolated from N(2)A (murine neuroblastoma) cells, rat brain and rat spinal cord, Different fibronectin isoforms have been isolated from brains of young and adult rats, indicating that the expression of MAG binding fibr onectin changes during development. (C) 2001 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.