A novel Akt/PKB-interacting protein promotes cell adhesion and inhibits familial amyotrophic lateral sclerosis-linked mutant SOD1-induced neuronal death via inhibition of PP2A-mediated dephosphorylation of Akt/PKB.
Akt/Protein Kinase B (PKB) family proteins (Akts), consisting of Akt1, 2, and 3, play a crucial role in multiple biological processes. We recently demonstrated that activation of Akt3 by the autosomal-recessive familial amyotrophic lateral sclerosis (ALS)-linked gene 2 (ALS2) product, alsinLF, led to the suppression of motoneuronal death induced by familial ALS-related mutant superoxide dismutase-1 (SOD1). To characterize the mechanism of neuroprotection mediated by Akt3 in detail, we performed a yeast two-hybrid system using Akt3 as a bait and identified BTBD10 as a novel Akt-interacting protein with a BTB/POZ domain. BTBD10 equally binds to any Akt. Overexpression of BTBD10 increased phosphorylation levels of Akts at both Thr(308) and Ser(473) while the reduction of the endogenous BTBD10 level resulted in a decrease in the phosphorylation levels of Akts. In vitro analysis indicated that BTBD10 bound to protein phosphatase 2A (PP2A) and inhibited dephosphorylation of Akts by PP2A. In agreement with BTBD10-mediated upregulation of the Akt phosphorylation levels, enforced expression of BTBD10 led to the suppression of mutant SOD1-induced neuronal death. Furthermore, overexpression of BTBD10 accelerated cell growth by enhancing cell adhesion. Given its ubiquitous expression, BTBD10 appears to behave as a suppressor of cell death including neuronal cell death related to ALS and an enhancer of cell growth via its positive regulation of Akt phosphorylation.
Nawa
Mikiro
M
Department of Anatomy, KEIO University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
Kanekura
Kohsuke
K
Hashimoto
Yuichi
Y
Aiso
Sadakazu
S
Matsuoka
Masaaki
M
D000690:Amyotrophic Lateral Sclerosis / Q000201:enzymology* / Q000235:genetics; D000818:Animals; D019556:COS Cells; D002448:Cell Adhesion; D016923:Cell Death; D049109:Cell Proliferation; D002522:Chlorocebus aethiops; D003593:Cytoplasm; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D009154:Mutation; D009474:Neurons / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D054648:Protein Phosphatase 2 / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D015398:Signal Transduction; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*; D000072105:Superoxide Dismutase-1; D013997:Time Factors; D014162:Transfection; D020798:Two-Hybrid System Techniques
C494432:BTBD10 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; C000606290:SOD1 protein, human; C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; C491754:AKT3 protein, human; C514862:Akt1 protein, mouse; C494922:Akt2 protein, mouse; C491753:Akt3 protein, mouse; D051057:Proto-Oncogene Proteins c-akt; D054648:Protein Phosphatase 2