Properly formed but improperly localized synaptic specializations in the absence of laminin alpha4

Modification of the laminin alpha 4 chain by chondroitin sulfate attachment to its N-terminal domain

The N-terminal domain of laminin alpha 4 chains corresponds to a short rod-like structure which after recombinant production was found to be modified by chondroitin sulfate. Substitution occurred mainly to a single serine in its N-terminal ASGDG sequence. A similar yet partial modification was also demonstrated for the alpha 4 chain present in extracts of adult mouse tissues. Antibodies to the fragment were useful to demonstrate a relatively high content of alpha 4 in several tissues and for the immunolocalization in various blood vessels, some basement membranes and interstitial regions.