Differential in vitro degradation of particular Fos family members expressed by kainic acid in nuclear and cytosolic fractions of murine hippocampus

Citation
T. Manabe et al., Differential in vitro degradation of particular Fos family members expressed by kainic acid in nuclear and cytosolic fractions of murine hippocampus, J NEUROSC R, 64(1), 2001, pp. 34-42
Citations number
27
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
JOURNAL OF NEUROSCIENCE RESEARCH
ISSN journal
0360-4012 → ACNP
Volume
64
Issue
1
Year of publication
2001
Pages
34 - 42
Database
ISI
SICI code
0360-4012(20010401)64:1<34:DIVDOP>2.0.ZU;2-8
Abstract
Mice were injected with kainic acid (KA) at a convulsive dose, followed by homogenization of the hippocampus in the presence of different protease and phosphatase inhibitors, and subsequent preparation of nuclear and cytosoli c fractions. An intraperitoneal injection of KA resulted in marked expressi on of particular Fos family members, including c-Fos, Fra-2, and Fos-B, but not Fra-1 proteins, in both fractions 2 to 18 h after administration. Thes e fractions were individually incubated at 30 degreesC for 1 to 18 h for de termination of in vitro degradation. Similarly rapid degradation was seen w ith c-Fos protein between nuclear fractions obtained 2 and 18 h after admin istration, while no significant degradation was found for c-Fos protein in cytosolic fractions obtained 2 h after administration during incubation. By contrast, in vitro incubation led to rapid degradation of c-Fos protein in cytosolic fractions obtained 18 h after administration. Degradation profil es were peculiar to each member protein in nuclear and cytosolic fractions obtained 2 and 18 h after administration. Dialysis prevented degradation of c-Fos protein in nuclear fractions without markedly affecting that in cyto solic fractions in a manner independent of the time after administration. T he addition of inhibitors for phosphatases, but not for proteases, accelera ted the degradation of c-Fos protein in nuclear fractions previously dialyz ed. These results suggest that in vivo KA signals may modulate heterologous machineries responsible for breakdown of each Fos family member in a uniqu e manner in nuclear fractions, rather than cytosolic fractions, of murine h ippocampus. (C) 2001 Wiley-Liss, Inc.