MGH Center for Systems Biology, Division of Nephrology, Massachusetts General Hospital, Boston, Massachusetts, United States of America.
PLoS One. 2012;7(9):e45395. doi: 10.1371/journal.pone.0045395. Epub 2012 Sep 20.
The vacuolar proton-pumping ATPase (V-ATPase) is the main mediator of intracellular organelle acidification and also regulates transmembrane proton (H(+)) secretion, which is necessary for an array of physiological functions fulfilled by organs such as the kidney, male reproductive tract, lung, bone, and ear. In this study we characterize expression of the V-ATPase in the main olfactory epithelium of the mouse, as well as a functional role for the V-ATPase in odor detection. We report that the V-ATPase localizes to the apical membrane microvilli of olfactory sustentacular cells and to the basolateral membrane of microvillar cells. Plasma membrane V-ATPases containing the B1 subunit isoform are not detected in olfactory sensory neurons or in the olfactory bulb. This precise localization of expression affords the opportunity to ascertain the functional relevance of V-ATPase expression upon innate, odor-evoked behaviors in B1-deficient mice. This animal model exhibits diminished innate avoidance behavior (revealed as a decrease in freezing time and an increase in the number of sniffs in the presence of trimethyl-thiazoline) and diminished innate appetitive behavior (a decrease in time spent investigating the urine of the opposite sex). We conclude that V-ATPase-mediated H(+) secretion in the olfactory epithelium is required for optimal olfactory function.
液泡型质子泵 ATP 酶（V-ATPase）是细胞内细胞器酸化的主要介质，也调节跨膜质子（H(+)）分泌，这对于肾脏、男性生殖道、肺、骨和耳等器官的一系列生理功能是必要的。在这项研究中，我们描述了 V-ATPase 在小鼠主要嗅觉上皮中的表达，以及 V-ATPase 在气味检测中的功能作用。我们报告说，V-ATPase 定位于嗅觉支持细胞的顶膜微绒毛和微绒毛细胞的基底外侧膜。在嗅觉感觉神经元或嗅球中未检测到含有 B1 亚基同工型的质膜 V-ATPase。这种精确的表达定位为确定 B1 缺陷型小鼠先天、气味诱发行为中 V-ATPase 表达的功能相关性提供了机会。这种动物模型表现出先天回避行为的减少（表现为在三甲基噻唑啉存在时冻结时间减少和嗅探次数增加）和先天食欲行为的减少（花在调查异性尿液上的时间减少）。我们得出结论，嗅觉上皮中 V-ATPase 介导的 H(+)分泌对于最佳嗅觉功能是必需的。
