Journal of Neuroscience, Vol 5, 468-476, Copyright © 1985 by Society for Neuroscience
Cell surface Thy-1-cross-reactive glycoprotein in cultured PC12 cells: modulation by nerve growth factor and association with the cytoskeleton
C Richter-Landsberg, LA Greene and ML Shelanski
In cultured PC12 rat pheochromocytoma cells, nerve growth factor (NGF)
selectively stimulated the incorporation of [3H]fucose into a glycoprotein
of apparent Mr approximately 25,000, as determined by sodium dodecyl
sulfate-gel electrophoresis. Neither dibutyryl cyclic adenosine
3':5'-monophosphate nor epidermal growth factor mimicked this effect. Using
gradient gels, the affected protein was resolved into two closely migrating
bands. Enhancement of labeling was present by 1 to 2 days of treatment with
NGF and was maximal after 4 to 7 days. Short- term extraction of PC12 cell
monolayer cultures with Triton X-100 left the 25,000-dalton glycoprotein
associated with the detergent-resistant cytoskeletal fraction. The Mr
approximately 25,000 glycoprotein was shown to be immunologically
cross-reactive with Thy-1.1 antigen by indirect immunoprecipitation with
monoclonal Thy-1.1 antibodies. Anti- Thy-1.1 labeling, as demonstrated by
indirect immunofluorescence, was distributed on PC12 cell bodies and along
neuritic processes and remained attached to the cytoskeleton as part of the
surface lamina of cells treated and untreated with NGF. The selective
increase of the Mr approximately equal to 25,000 glycoprotein in
NGF-treated cultures was also paralleled by increases in material
immunoprecipitated from fucose- labeled cells with anti Thy-1.1 monoclonal
antibodies. Immunoprecipitations with extracts of [35S]methionine-labeled
cultures indicated that NGF causes an increase in synthesis, rather than
merely glycosylation, of the 25,000-dalton/Thy-1-cross-reactive protein.
The effect of NGF on this protein was blocked by inhibitors of RNA
synthesis, suggesting involvement of a transcription-dependent
mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)