Primary sequence of a motor neuron-selective adhesive site in the synaptic basal lamina protein S-laminin.
S-laminin, a novel homolog of laminin, is concentrated in a subset of basal laminae including the basal lamina that passes between motor nerve terminals and muscle fibers at the neuromuscular junction. Here we used recombinant fragments to localize a neuronal attachment site to the C-terminal 10% of s-laminin. We then used synthetic peptides spanning the active fragment to identify the primary sequence of the adhesive site as Leu-Arg-Glu (LRE): neurons attach to an immobilized LRE-containing peptide, and soluble LRE blocks attachment of neurons to the s-laminin fragment. Whereas ciliary ganglion neurons (which normally innervate muscle fibers) adhered well both to laminin and to an s-laminin fragment, sensory and central neurons and several neuronal cell lines all adhered well to laminin but poorly to the s-laminin fragment. Together, these results define a motor neuron-selective attachment site on s-laminin.
Hunter
D D
DD
Department of Anatomy and Neurobiology, Washington University School of Medicine, St Louis, Missouri 63110.
Porter
B E
BE
Bulock
J W
JW
Adams
S P
SP
Merlie
J P
JP
Sanes
J R
JR
D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D007797:Laminin / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000502:physiology*; D010455:Peptides / Q000138:chemical synthesis / Q000494:pharmacology; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013569:Synapses / Q000502:physiology*
D007797:Laminin; D010455:Peptides; D011993:Recombinant Fusion Proteins; C058783:laminin beta2; D004247:DNA