Expression of smg p25A/rab 3A guanine nucleotide dissociation inhibitor (GDI) in neurons and glial cells from rat brain.
smg p25A/rab 3A is a member of the rab family of small guanosine 5'-trisphosphate (GTP)-binding proteins, which are postulated to act as specific regulators of membrane trafficking in exocytosis and endocytosis. In neural tissues, smg p25A/rab 3A is expressed only in neurons but not in glia. In this study, expression of a regulatory protein for smg p25A/rab 3A, guanine nucleotide dissociation inhibitor (smg p25A/rab 3A GDI), in neurons and glia isolated from rat brain was examined. The smg p25A/rab 3A GDI mRNa was detected as early as on gestational day 14 in the fetal brain, and its level reached a maximum 5 days after birth. By immunoblot analysis, smg p25A/rab 3A GDI was detected in the homogenate of rat hippocampus as well as in that of astrocytes in primary culture. By immunocytochemical analysis, the smg p25A/rab 3A GDI immunoreactivity was detected in hippocampal neurons and oligodendrocytes. The immunoreactivity of astrocytes was much lower than that of neurons and oligodendrocytes. These results indicate that smg p25A/rab 3A GDI may play a fundamental role in membrane trafficking both neurons and glia by interacting with multiple rab family proteins.
Motoike
T
T
Department of Pediatrics, Kobe University School of Medicine, Japan.
Sano
K
K
Nakamura
H
H
Takai
Y
Y
D000818:Animals; D000911:Antibodies, Monoclonal; D001253:Astrocytes / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D002478:Cells, Cultured; D019204:GTP-Binding Proteins / Q000032:analysis / Q000096:biosynthesis*; D005699:Galactosylceramides / Q000032:analysis; D006624:Hippocampus / Q000378:metabolism*; D007150:Immunohistochemistry; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D009836:Oligodendroglia / Q000378:metabolism*; D051381:Rats; D020692:rab3 GTP-Binding Proteins
D000911:Antibodies, Monoclonal; D005699:Galactosylceramides; D009419:Nerve Tissue Proteins; D019204:GTP-Binding Proteins; D020692:rab3 GTP-Binding Proteins