Expression of septin 3 isoforms in human brain.
Septin 3 is a novel member of the septin subfamily of GTPase domain proteins. Human septin 3 was originally cloned during a screening of genes expressed in human teratocarcinoma cells induced to differentiate with retinoic acid. Alternative splicing of the septin 3 gene transcript produces two isoforms, A and B, in the human brain, though their regional expression and physiological function remain to be determined. The purpose of the present study was to identify the expression patterns of human septin 3 isoforms in normal human brain and a human neuroblastoma cell line, SH-SY5Y, after retinoic acid-induced differentiation. The expression and distribution patterns of septin 3 isoforms A and B were similar and resembled that of another septin, CDCrel-1. Septin 3A and 3B were expressed in normal human brain in a region-specific manner, with the highest level in the temporal cortex and hippocampus and the lowest level in the brainstem regions. Prominent immunoreactivity was observed diffusely in the neocortices in association with neuropils and punctate structures suggestive of synaptic junctions. Immunoprecipitation studies revealed that septin 3A, 3B, and CDCrel-1 form a complex in the frontal cortex of human brain. These findings, taken together, suggest that septin 3A and 3B, along with CDCrel-1, play some fundamental role(s) in synaptogenesis and neuronal development.
Takehashi
Masanori
M
Laboratory of Molecular Clinical Chemistry, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
Tanaka
Seigo
S
Stedeford
Todd
T
Banasik
Marek
M
Tsukagoshi-Nagai
Hiroe
H
Kinoshita
Noriaki
N
Kawamata
Toshio
T
Ueda
Kunihiro
K
D000906:Antibodies / Q000276:immunology; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D018797:Cell Cycle Proteins / Q000032:analysis; D002454:Cell Differentiation; D002460:Cell Line; D005625:Frontal Lobe / Q000737:chemistry; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D007120:Immunochemistry; D047468:Immunoprecipitation; D011485:Protein Binding; D020033:Protein Isoforms / Q000032:analysis / Q000235:genetics / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis; D058112:Septins; D014212:Tretinoin / Q000494:pharmacology; D015854:Up-Regulation
D000906:Antibodies; D018797:Cell Cycle Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D014212:Tretinoin; D020558:GTP Phosphohydrolases; C109366:SEPTIN5 protein, human; D058112:Septins; C407343:septin 3