Investigation on functional mechanisms of novel globin proteins under oxidative stress conditions by protein engineering

2016 Fiscal Year Final Research Report

• Project/Area Number: 26440047
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Functional biochemistry
• Research Institution: The University of Tokyo
• Principal Investigator: WAKASUGI Keisuke 東京大学, 大学院総合文化研究科, 准教授 (20322167)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 蛋白質 / ストレス / シグナル伝達 / 生理活性

Outline of Final Research Achievements

Human neuroglobin (Ngb) protects neuronal cells under conditions of oxidative stress. We previously showed that human Ngb acts as a guanine nucleotide dissociation inhibitor (GDI) for the α-subunits of heterotrimeric Gi/o proteins and inhibits the decrease in cAMP concentration, leading to protection against cell death. In the present study, we used an eukaryotic expression vector driving high-level expression of human wild-type Ngb or Ngb mutants that either exhibit or lack GDI activities in human cells. We demonstrated that the GDI activity of human Ngb is tightly correlated with its neuroprotective activity. We further demonstrated that Glu53, Glu60, and Glu118 of human Ngb are crucial for both the neuroprotective activity and interaction with Gαi1. Moreover, we showed that Lys46, Lys70, Arg208, Lys209, and Lys210 residues of Gαi1 are important for binding to human Ngb. We propose a molecular docking model of the complex between human Ngb and Gαi1.

Free Research Field

生物学