Energy requirements for pigment aggregation in fundulus melanophores.
Energy requirements for pigment aggregation in fundulus melanophores.
复制标题
眼底黑色素细胞中色素聚集的能量需求。
DOI：
10.1002/cm.970040604
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
J. Rosenbaum
中科院分区：
文献类型：
--
作者：
T. Clark;J. Rosenbaum
硬骨鱼类色素细胞充满了单个的色素颗粒，这些色素颗粒迅速聚集到细胞中心，或者响应环境刺激而分散在整个细胞质中。微管似乎是色素聚集（向细胞中心移动）所必需的，最近的研究结果表明，动力蛋白样ATP酶可能参与力的产生。然而，根据以前的研究，有人认为色素聚集不直接需要能量，这一观点支持颗粒运动中弹性成分的参与。为了进一步研究这一点，我们重新研究了色素聚集的能量需求，使用完整的细胞和洗涤剂透化的细胞模型的底黑色素细胞。氧化磷酸化的毒物，即2，4-二硝基苯酚和NaCN，可逆地抑制黑素体响应肾上腺素的聚集。运动的抑制直接来自细胞内ATP的消耗，因为色素易位可以通过向裂解缓冲液中加入外源性ATP在透化细胞中重新激活。不可水解的类似物，包括β，γ-亚氨基腺苷-5 '-三磷酸（AMPPNP）、β，γ-亚甲基腺苷-5'-三磷酸（AMPPCP）和ATP γ S，在运动的再激活中不会取代ATP。类似地，其他核苷酸如ADP、AMP、GTP、CTP和ITP在经受去污剂裂解的代谢中毒细胞中支持黑素体聚集的能力有限。ATP本身对完整的细胞没有影响。这些结果表明，黑素小体聚集是ATP依赖性和能量驱动的，并与粒子运动中的力转导ATP酶的作用一致。
Teleost chromatophores are filled with individual pigment granules that rapidly aggregate to the cell center or become dispersed throughout the cytoplasm in response to environmental stimuli. Microtubules appear to be required for pigment aggregation (movement toward the cell center), and recent findings have suggested that a dynein-like ATPase may participate in force production. Based on previous studies, however, it has been argued that pigment aggregation does not require energy directly, a view that supports the involvement of an elastic component in granule movement. To examine this point further, we have reinvestigated the energy requirements for pigment aggregation using both intact cells and detergent-permeabilized cell models of Fundulus melanophores. Poisons of oxidative phosphorylation, namely, 2,4 dinitrophenol and NaCN, reversibly inhibit melanosome aggregation in response to adrenaline. Inhibition of movement results directly from depletion of intracellular ATP, since pigment translocation can be reactivated in permeabilized cells by the addition of exogenous ATP to the lysis buffer. Non-hydrolyzable analogues, including beta, gamma-imidoadenosine-5'-triphosphate (AMPPNP), beta, gamma-methylene adenosine-5'-triphosphate (AMPPCP), and ATP gamma S, will not substitute for ATP in reactivation of movement. Similarly, other nucleotides such as ADP, AMP, GTP, CTP, and ITP, have limited ability to support melanosome aggregation in metabolically poisoned cells subjected to detergent lysis. ATP itself has no effect on intact cells. These results indicate that melanosome aggregation is ATP-dependent and energy-driven, and are consistent with a role for a force-transducing ATPase in particle movement.