e near the Ca2+-bowl of the BKCa channel a subunit to alter Ca2+ sensing. Perspectives Chronic hypoxia during gestation increases incidence of preeclampsia and fetal intrauterine growth restriction due to maladaptation of the uteroplacental circulation. However, mechanisms underlying these effects remain poorly understood. Heightened oxidative stress is associated with 10440374 a variety of pathophysiological conditions including preeclampsia. The present study demonstrates that chronic hypoxia during gestation upregulates Nox2 expression in uterine arteries leading to increased ROS production, which in turn results in suppressed BKCa channel activity and increased uterine arterial myogenic tone. Thus, the present finding provides a mechanistic understanding of heightened oxidative stress in maladaptation of the uteroplacental circulation associated with chronic hypoxia during gestation, and may shed light on a causative factor in pathophysiology of preeclampsia. Subunit of Bacillus subtilis F1-ATPase Relieves MgADP Inhibition Junya Mizumoto1, Yuka Kikuchi1, Yo-Hei Nakanishi1, Naoto Mouri1, Anrong Cai1, Tokushiro Ohta1, Takamitsu Haruyama1, Yasuyuki Kato-Yamada1,2 1 Department of Life Science, Rikkyo University, Tokyo, Japan, 2 Research Center for Life Science, Rikkyo University, Tokyo, Japan Abstract MgADP inhibition, which is considered as a part of the regulatory system of ATP synthase, is a well-known process common to all F1-ATPases, a soluble component of ATP synthase. The entrapment of inhibitory MgADP at catalytic sites terminates catalysis. Regulation by the subunit is a common mechanism among F1-ATPases from bacteria and plants. The relationship between these two forms of regulatory mechanisms is obscure because it is 25162172 difficult to distinguish which is active at a particular moment. Here, using F1-ATPase from Bacillus subtilis, which is strongly affected by MgADP inhibition, we can distinguish MgADP inhibition from regulation by the subunit. The subunit did not inhibit but activated BF1. We conclude that the subunit relieves BF1 from MgADP inhibition. Citation: Mizumoto J, Kikuchi Y, Nakanishi Y-H, Mouri N, Cai A, et al. Subunit of Bacillus subtilis F1-ATPase Relieves MgADP Inhibition. PLoS ONE 8: e73888. doi:10.1371/journal.pone.0073888 Editor: Oleg Y. Dmitriev, University of Saskatchewan, Canada Received March 27, 2013; Accepted July 23, 2013; Published August 13, 2013 Copyright: 2013 Mizumoto et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and MedChemExpress CSP-1103 source are credited. Funding: This work was supported in parts by Grants-in-Aid for Scientific Research for Young Scientists , the Strategic Research Foundation Grant-aided Project for Private Universities from the Ministry of Education, Culture, Sports, Science and Technology of Japan, and Rikkyo University Special Fund for Research fro Rikkyo University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist. E-mail: [email protected] Current address: Bio-AFM Frontier Research Center, College of Science and Engineering, Kanazawa University Introduction FoF1-ATPase/synthase catalyzes ATP synthesis from ADP and inorganic phosphate coupled with the flow of H+ driven by the