Journal
JOURNAL OF CELL BIOLOGY
Volume 154, Issue 2, Pages 435-445Publisher
ROCKEFELLER UNIV PRESS
DOI: 10.1083/jcb.200105003
Keywords
neurexin; dystroglycan; synapse; LNS domain; laminin
Categories
Funding
- NIMH NIH HHS [R01-MH52804, R01 MH052804] Funding Source: Medline
Ask authors/readers for more resources
In nonneuronal cells, the cell surface protein dystroglycan links the intracellular cytoskeleton (via dystrophin or utrophin) to the extracellular matrix (via laminin, agrin, or perlecan). Impairment of this linkage is instrumental in the pathogenesis of muscular dystrophies. In brain, dystroglycan and dystrophin are expressed on neurons and astrocytes, and some muscular dystrophies cause cognitive dysfunction; however, no extracellular binding partner for neuronal dystroglycan is known. Regular components of the extracellular matrix, such as laminin, agrin, and perlecan, are not abundant in brain except in the perivascular space that is contacted by astrocytes but not by neurons, suggesting that other ligands for neuronal dystroglycan must exist. We have now identified alpha- and beta -neurexins, polymorphic neuron-specific cell surface proteins, as neuronal dystro-glycan receptors. The extracellular sequences of alpha- and beta -neurexins are largely composed of laminin-neurexin-sex hormone-binding globulin (LNS)/laminin G domains, which are also found in laminin, agrin, and perlecan, that are dystroglycan ligands. Dystroglycan binds specifically to a subset of the LNS domains of neurexins in a tight interaction that requires glycosylation of dystroglycan and is regulated by alternative splicing of neurexins. Neurexins are receptors fr the excitatory neurotoxin alpha -latrotoxin; this toxin competes with dystroglycan for binding, suggesting overlapping binding sites on neurexins for dystroglycan and alpha -latrotoxin. Our data indicate that dystroglycan is a physiological ligand for neurexins and that neurexins' tightly regulated interaction could mediate cell adhesion between brain cells.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available