Brain synapses contain inducible forms of the transcription factor NF-kappa B.
We investigated the rat brain for the presence and activation state of the inducible transcription factor NF-kappa B. Two forms of NF-kappa B containing the transactivating p65 subunit were found in all brain regions investigated. The majority of NF-kappa B was in an inducible cytoplasmic form by virtue of its association with the inhibitory subunit I kappa B. Significant amounts of inducible NF-kappa B forms were present in synaptosomes, as suggested by electrophoretic mobility shift assay and Western blot analysis of subcellular brain fractions. A synaptic localization of NF-kappa B was further evident from immunostaining of inner and outer plexiform layers of the retina with an antibody directed against the p50 subunit of NF-kappa B. In cerebral cortex and striatum, NF-kappa B-specific antibodies showed a punctate immunostaining partially overlapping with that for the synaptic marker protein synaptophysin. NF-kappa B is thus the first transcription factor found in synapses of neurons. With its unusual subneuronal localization, the inducible transcription factor has the potential to function as retrograde messenger mediating stimulus-response coupling and long-term changes in gene expression following presynaptic stimulation.
Kaltschmidt
C
C
Laboratory for Molecular Biology, Gene Center, Martinsried, Germany.
Kaltschmidt
B
B
Baeuerle
P A
PA
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D001923:Brain Chemistry / Q000235:genetics*; D002478:Cells, Cultured; D004586:Electrophoresis; D005786:Gene Expression Regulation / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000032:analysis* / Q000096:biosynthesis; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000737:chemistry; D013569:Synapses / Q000737:chemistry*; D013574:Synaptosomes / Q000737:chemistry
D016328:NF-kappa B; D009419:Nerve Tissue Proteins