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Somatodendritic localization of EFA6A, a guanine nucleotide exchange factor for ADP‐ribosylation factor 6, and its possible interaction with α‐actinin in dendritic spines
Author(s) -
Sakagami Hiroyuki,
Honma Takashi,
Sukegawa Jun,
Owada Yuji,
Yanagisawa Teruyuki,
Kondo Hisatake
Publication year - 2007
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2007.05345.x
Subject(s) - guanine nucleotide exchange factor , hippocampal formation , dendritic spine , microbiology and biotechnology , adp ribosylation factor , biology , spectrin , mossy fiber (hippocampus) , cytoskeleton , chemistry , biochemistry , dentate gyrus , neuroscience , cell , signal transduction , golgi apparatus , endoplasmic reticulum
EFA6A is a member of the guanine nucleotide exchange factors that can specifically activate ADP ribosylation factor 6 (ARF6). In this study, we identified α‐actinin‐1 as a possible interacting protein with EFA6A by the yeast two‐hybrid screening with its C‐terminal region as bait. The central region of α‐actinin‐1 containing a part of spectrin repeat 1 and spectrin repeats 2–3 is responsible for this interaction. In the hippocampal formation, EFA6A immunoreactivity occurred at a high level as numerous fine puncta in the strata oriens, radiatum, lacunosum‐moleculare of the hippocampal CA1–3 subfields and the dentate molecular layer, whereas the immunoreactivity was faint in the neuronal cell layers and the stratum lucidum, the mossy fiber‐recipient layer of the CA3 subfield. Double‐immunofluorescent analyses revealed a partial overlapping of EFA6A and α‐actinin at the dendritic spines of in vivo and cultured hippocampal neurons. Our present findings suggest that EFA6A may form a protein complex with α‐actinin and activate ARF6 in close proximity of the actin cytoskeleton and membrane proteins in the dendritic spines.