Adrenalectomy facilitates the ATAT1 expression and α-tubulin acetylation in ACTH-producing corticotrophs
Adrenalectomy facilitates the ATAT1 expression and α-tubulin acetylation in ACTH-producing corticotrophs
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肾上腺切除术促进促肾上腺皮质激素细胞中 ATAT1 表达和 α-微管蛋白乙酰化
DOI：
10.1007/s00441-016-2441-7
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Hagiwara H
中科院分区：
文献类型：
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作者：
Nakakura T;Nemoto T;Suzuki T;Asano-Hoshino A;Tanaka H;Arisawa K;Nishijima Y;Kiuchi Y;Hagiwara H
微管在内分泌细胞分泌颗粒的胞内运输、有丝分裂和细胞形态的维持中起重要作用，由α-和β-微管蛋白的异二聚体组成。α-微管蛋白N-乙酰基转移酶1（ATAT 1）是一种将α-微管蛋白40位赖氨酸乙酰化的酶，它不仅具有稳定微管结构和形成初级纤毛的功能，而且还参与神经元的囊泡运输。然而，ATAT 1的定位和α-微管蛋白乙酰化在垂体内分泌细胞中的作用仍然知之甚少。垂体前叶中的促肾上腺皮质激素细胞产生并分泌促肾上腺皮质激素（ACTH）。虽然据报道，切除肾上腺（ACTH的靶器官）可促进促肾上腺皮质激素细胞的ACTH合成和分泌，并诱导其细胞器的结构改变，但α-微管蛋白的乙酰化是否参与促肾上腺皮质激素细胞的此类细胞内事件仍不确定。本研究观察了正常和肾上腺切除大鼠垂体中ATAT 1的表达、定位和α-微管蛋白的乙酰化。我们发现ATAT 1定位于正常垂体前叶内分泌细胞的高尔基体，肾上腺切除后ATAT 1的表达水平和α-微管蛋白的乙酰化水平增加。这些结果与ATAT 1乙酰化α-微管蛋白调节促肾上腺皮质激素细胞分泌颗粒的胞内转运的假说一致。
Microtubules play an important role in the intracellular transport of secretory granules in endocrine cells and in mitosis and the maintenance of cell morphology and are composed of heterodimers of α- and β-tubulin. α-TubulinN-acetyltransferase 1 (ATAT1), which acetylates the lysine residue at position 40 of α-tubulin, functions not only in stabilizing microtubule structures and forming the primary cilium assembly but also in vesicular trafficking in neurons. However, the localization of ATAT1 and the role of α-tubulin acetylation in endocrine cells in the pituitary are still poorly understood. Corticotrophs in the anterior lobe of the pituitary produce and secrete adrenocorticotropin (ACTH). Although removal of the adrenal gland, a target organ of ACTH, is reported to promote the synthesis and secretion of ACTH in corticotrophs and to induce structural alterations in their organelles, uncertainty remains as to whether the acetylation of α-tubulin is involved in such intracellular events of corticotrophs. We investigate the expression and localization of ATAT1 and the acetylation of α-tubulin in the pituitary of normal and adrenalectomized rats. We find that ATAT1 is localized to the Golgi apparatus of endocrine cells in the anterior lobe of normal pituitary and that the expression levels of ATAT1 and acetylation levels of α-tubulin increase following adrenalectomy. These results agree with the hypothesis that the acetylation of α-tubulin by ATAT1 regulates the intracellular transport of secretory granules in corticotrophs.