Distribution and expression of SNAP-25 immunoreactivity in rat brain, rat PC-12 cells and human SMS-KCNR neuroblastoma cells.
Immunocytochemical, immunoblotting and in situ hybridization studies were used to map the distribution of SNAP-25 protein and mRNA in the rodent nervous system. These experiments demonstrated that subsets of neurons expressed SNAP-25, and that several patterns of expression emerged: SNAP-25 expression in caudate nucleus was initially concentrated in axons, which subsequently was localized in presynaptic regions of these axons. Other regions, typified by neocortex, showed developmental increases and persistent adult neuronal immunoreactivity for SNAP-25. Finally, olfactory bulb contained neurons which initially expressed SNAP-25, but lost expression during maturation. Additional studies in cultured human and rat cell lines derived from neural crest suggested that SNAP-25 is expressed in such lines, but not in glial or fibroblast lines. Differentiation of rat PC-12 cells with nerve growth factor failed to alter steady-state levels of SNAP-25 protein; similar responses were seen in human SMS-KCNR neuroblastoma cells differentiated using retinoic acid. The presence of SNAP-25 in presynaptic regions of numerous neuronal subsets and in neural crest cell lines suggests that this protein subserves an important function in neuronal tissues.
Oyler
G A
GA
Department of Pharmacology, Pennsylvania State University College of Medicine, Hershey 17033.
Polli
J W
JW
Higgins
G A
GA
Wilson
M C
MC
Billingsley
M L
ML
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D005070:Evans Blue; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins / Q000276:immunology / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D016716:PC12 Cells; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D012867:Skin / Q000378:metabolism; D050825:Synaptosomal-Associated Protein 25; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D001798:Blood Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C494208:SNAP25 protein, human; C494210:Snap25 protein, rat; D050825:Synaptosomal-Associated Protein 25; D005070:Evans Blue; D014212:Tretinoin