Association of Thy-1 differentiation alloantigen with synaptic complexes isolated from mouse brain.
Conventional fractionation procedures were used in an effort to define the subcellular distribution of the Thy-1 alloantigen in whole mouse brain. After discontinuous sucrose density gradient centrifugation of isotonic postnuclear particulate fractions, the bulk of Thy-1 was recovered in regions of the gradients containing synaptosomes. The synaptosome fraction that banded at 1.2 M sucrose yielded a specific activity for Thy-1 significantly greater than the synaptosomes separating at 1.4 M sucrose. Osmotic lysis of both synaptosome fractions resulted in further enrichment in Thy-1 activity, with no concomitant decrease in yields. The synaptosomal membranes obtained in this way were subsequently treated with Triton X-100 and subjected to further density gradient centrifugation. Although the detergent treatment resulted in some loss of antigenic activity, the gradient fractions that contained Thy-1 also were found by electron microscopy to be richest in synaptic junctional complexes. These findings suggest that Thy-1 is associated with synaptosomes and synaptic junctional complexes and therefore may be involved in the formation and/or maintenance of synaptic connections.
D000818:Animals; D001921:Brain / Q000276:immunology* / Q000648:ultrastructure; D007519:Isoantigens; D051379:Mice; D008815:Mice, Inbred Strains; D011092:Polyethylene Glycols; D013347:Subcellular Fractions / Q000276:immunology; D013570:Synaptic Membranes / Q000276:immunology*; D013574:Synaptosomes / Q000276:immunology*
D007519:Isoantigens; D011092:Polyethylene Glycols