Regulation of the distribution of carotenoid droplets in goldfish xanthophores and possible implication to secretory processes.
Regulation of the distribution of carotenoid droplets in goldfish xanthophores and possible implication to secretory processes.
复制标题
金鱼黄色细胞中类胡萝卜素液滴分布的调节及其对分泌过程的可能影响。
DOI：
10.1002/cm.970100119
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发表时间：
1988
影响因子：
--
通讯作者：
Taylor,JD
中科院分区：
文献类型：
--
作者：
Tchen,TT;Lo,SJ;Lynch,TJ;Palazzo,RE;Peng,G;Walker,GR;Wu,BY;Yu,FX;Taylor,JD
在金鱼黄细胞中，色素聚集体的形成需要：(1)色素细胞器（类胡萝卜素液滴）蛋白p57处于非磷酸化状态；(2)色素细胞器的自结合以微管独立的方式发生；(3)色素细胞器通过p57与微管结合。在完全聚集状态下，色素细胞器是完全静止的。色素的分散是由cAMP依赖性蛋白激酶激活引起的，该蛋白激酶磷酸化p57，并通过依赖于F - actin和细胞质因子的活性过程使色素分散。该因子不是atp酶，其功能尚不清楚。然而，其在不同组织中的丰度与组织的分泌活性相似，表明黄嘌呤的分泌与色素在黄嘌呤细胞中的分散相似。颜料分散的动力机制尚不清楚。实验结果表明，从分散色素细胞中分离的色素细胞器具有与肌凝蛋白atp酶相当的相关肌动蛋白和atp酶活性。该atp酶可能是一种相对分子质量约为72,000的细胞器蛋白，不太可能是离子泵。没有相关肌动蛋白的分离色素细胞器的atp酶活性降低了5倍。这种细胞器atp酶是否为色素分散的动力仍在研究中。人们对色素聚集的过程知之甚少，支持和反对中间细丝参与的结果相互矛盾。
In goldfish xanthophores, the formation of pigment aggregate requires: (1) that a pigment organelle (carotenoid droplet) protein p57 be in the unphosphorylated state; (2) that self‐association of pigment organelles occur in a microtubule‐independent manner; and (3) that pigment organelles via p57 associate with microtubules. In the fully aggregated state, the pigment organelles are completely stationary. Pigment dispersion is initiated by activation of a cAMP‐dependent protein kinase, which phosphorylates p57 and allows pigment dispersion via an active process dependent on F‐actin and a cytosolic factor. This factor is not an ATPase, and its function is unknown. However, its abundance in different tissues parallels secretory activity of the tissues, suggesting a similarity between secretion and pigment dispersion in xanthophores. The identity of the motor for pigment dispersion is unclear. Experimental results show that pigment organelles isolated from cells with dispersed pigment have associated actin and ATPase activity comparable to myosin ATPase. This ATPase is probably an organelle protein of relative molecular mass ∼72,000, and unlikely to be an ion pump. Isolated pigment organelles without associated actin have 5× lower ATPase activity. Whether this organelle ATPase is the motor for pigment dispersion is under investigation. The process of pigment aggregation is poorly understood, with conflicting results for and against the involvement of intermediate filaments.