Role of nitric oxide and mitochondria in control of firefly flash
Role of nitric oxide and mitochondria in control of firefly flash
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DOI：
10.1093/icb/44.3.213
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发表时间：
2004-06-01
影响因子：
2.6
通讯作者：
Trimmer, BA
中科院分区：
文献类型：
--
作者：
Aprille, JR;Lagace, CJ;Trimmer, BA
在萤火虫发光器官的发光细胞（光细胞）中，线粒体聚集在细胞外围，位于气管供气和需氧生物发光反应物之间，这些反应物被隔离在更集中的过氧化物酶体中。这种相对定位表明线粒体可以控制光反应所需的氧气。我们假设活跃的细胞呼吸会使光细胞的内部区域相对缺氧，并且产生生物发光的“开启”信号可能取决于对线粒体耗氧量的抑制，这将使输送的氧气穿过线粒体外周区到达细胞内部深处的过氧化物酶体。我们最近发表了外源一氧化氮在完整的萤火虫中诱导生物发光的研究；在解剖的灯笼中，一氧化氮介导章鱼胺诱导的生物发光，并且一氧化氮合酶在发光器官的气管系统的细胞中丰富。其他实验表明，一氧化氮 (NO) 会抑制分离的灯笼线粒体的呼吸。强光可逆转抑制作用，关灯时这种抑制作用会解除。总而言之，这些结果支持这样的观点：NO 通过可逆抑制灯笼细胞中的线粒体呼吸来触发光产生，也可能在气管细胞中。数据还表明，生物发光本身可以缓解 NO 抑制，从而有助于快速开关。虽然其他机制可能在发挥作用，但与神经输入直接相关的一氧化氮生成似乎在控制闪光通讯信号的氧门中发挥着关键作用。
In light-producing cells (photocytes) of the firefly light organ, mitochondria are clustered in the cell periphery, positioned between the tracheolar air supply and the oxygen-requiring bioluminescent reactants which are sequestered in more centrally-localized peroxisomes. This relative positioning suggests that mitochondria could control oxygen availability for the light reaction. We hypothesized that active cellular respiration would make the interior regions of the photocytes relatively hypoxic, and that the "on" signal for production of bioluminescence might depend on inhibition of mitochondrial oxygen consumption, which would allow delivered oxygen to pass through the peripheral mitochondrial zone to reach peroxisomes deep in the cell interior. We published recently that exogenous NO induces bioluminescence in the intact firefly; that NO mediates octopamine-induced bioluminescence in the dissected lantern, and that nitric oxide synthase is abundant in cells of the tracheolar system of the light organ. Additional experiments showed that nitric oxide gas (NO) inhibits respiration in isolated lantern mitochondria. Inhibition is reversed by bright light, and this inhibition is relieved when the light is turned off. Altogether, the results support the idea that NO triggers light production by reversible inhibition of mitochondrial respiration in lantern cells, and probably in tracheolar cells as well. The data also suggest that the light of bioluminescence itself relieves NO inhibition thus contributing to rapid on/off switching. While other mechanisms may be in play, NO production that is directly related to neural input appears to have a key role in the oxygen gating that controls flash communication signals.