Age-related changes in composition of transcription factor, AP-1 complex in the rat brain.
We examined age-related changes in composition of transcription factor, activator protein-1 (AP-1) which binds to TPA responsive element (TRE) in the non-stimulated rat brain, using electrophoretic mobility-shift assay with immunodepletion/supershift assay. The total TRE-binding activity in the frontal cortex and the hippocampus of the aged rats markedly decreased to 66% and 43%, respectively, and TRE-bindings of AP-1 in both regions also decreased to 82% and 66%, respectively, with aging. Jun-Jun dimers accounted for approximately half of the total TRE-bindings and 80-90% of the AP-1 bindings, while there were fewer Fos-Jun dimers, in both examined regions of the non-stimulated adult. The proportion of active Fos-Jun heterodimers in the frontal cortex increased to up to half of the AP-1 bindings in the aged rats, indicating that cortical AP-1-related transcription may increase with aging even under the non-stimulated condition. In the hippocampus, inactive Jun-Jun homodimers became predominant in AP-1 with aging. This regional diversity of age-related changes in the composition of AP-1 in the brain may be related to changes or dysfunction in neuronal signal transduction in the aged.
Asanuma
M
M
Department of Neuroscience, Okayama University Medical School, Japan.
Kondo
Y
Y
Nishibayashi
S
S
Iwata
E
E
Nakanishi
T
T
Ogawa
N
N
D000375:Aging / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D001923:Brain Chemistry / Q000502:physiology*; D015342:DNA Probes; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation / Q000502:physiology; D016762:Genes, fos / Q000502:physiology; D016758:Genes, jun / Q000502:physiology; D006624:Hippocampus / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D051381:Rats; D011916:Rats, Inbred F344; D018808:Transcription Factor AP-1 / Q000737:chemistry / Q000378:metabolism*
D015342:DNA Probes; D018808:Transcription Factor AP-1