Widespread dysregulation of peptide hormone release in mice lacking adaptor protein AP-3.
Widespread dysregulation of peptide hormone release in mice lacking adaptor protein AP-3.
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DOI：
10.1371/journal.pgen.1003812
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发表时间：
2013
期刊：
影响因子：
4.5
通讯作者：
Asensio CS
中科院分区：
文献类型：
--
作者：
Sirkis DW;Edwards RH;Asensio CS
肽类激素、神经肽和许多生长因子的调节分泌依赖于它们分选成能够调节胞吐作用的大致密核心囊泡（LDCV）。LDCV在trans-Golgi网络中形成，但是将蛋白质分类到这种受调节的分泌途径的机制和产生LDCV的胞质机器仍然知之甚少。最近，我们使用RNAi筛选来鉴定异源四聚体衔接蛋白AP-3在调节分泌，特别是LDCV形成中的作用。事实上，缺乏AP-3的摩卡小鼠具有严重的神经和行为表型，但这已被归因于AP-3在内溶酶体而不是生物合成途径中的作用。因此，我们使用摩卡小鼠来确定AP-3的缺失是否也会在体内失调肽的释放。我们发现，肾上腺嗜铬细胞从摩卡咖啡动物表现出增加的组成性胞吐可溶性货物和LDCV膜蛋白，减少对刺激的反应。我们还观察到摩卡小鼠胰岛细胞胰岛素和胰高血糖素的基础释放增加，这表明肽类激素的释放存在全局性干扰。AP-3以普遍存在的和神经元的同种型存在，但是对单独和一起缺乏这些同种型的小鼠的分析表明，两者的缺失是复制摩卡突变对调节途径的影响所必需的。此外，我们发现，相关的衔接蛋白AP-1的损失有一个类似的影响，调节分泌，但加剧了AP-3 RNAi的效果，这表明不同的角色，两个衔接子在调节分泌途径。肽激素和神经肽的生理作用取决于它们对能够响应刺激调节胞吐的囊泡的分选。尽管由该途径释放的信号的多样性和重要性，但令人惊讶的是，对于与经历组成性释放的分泌囊泡相反的介导调节分泌的大致密核心囊泡（LDCV）的分选和实际形成所涉及的分子机制了解甚少。我们最近在细胞系中使用RNA干扰来确定衔接蛋白AP-3在分选到受调节的分泌途径中的需要，但这种作用在体内的重要性仍然未知。使用缺乏AP-3复合物的各种亚基的突变小鼠，我们现在表明AP-3确实是多种神经内分泌细胞类型中适当的、受调节的分泌所必需的。虽然AP-3以普遍存在和神经元形式存在，但我们也发现，单独的任一形式足以赋予调节分泌。结果表明，AP-3在调节肽类激素和神经肽的释放中起着新的和必要的作用。
The regulated secretion of peptide hormones, neural peptides and many growth factors depends on their sorting into large dense core vesicles (LDCVs) capable of regulated exocytosis. LDCVs form at the trans-Golgi network, but the mechanisms that sort proteins to this regulated secretory pathway and the cytosolic machinery that produces LDCVs remain poorly understood. Recently, we used an RNAi screen to identify a role for heterotetrameric adaptor protein AP-3 in regulated secretion and in particular, LDCV formation. Indeed, mocha mice lacking AP-3 have a severe neurological and behavioral phenotype, but this has been attributed to a role for AP-3 in the endolysosomal rather than biosynthetic pathway. We therefore used mocha mice to determine whether loss of AP-3 also dysregulates peptide release in vivo. We find that adrenal chromaffin cells from mocha animals show increased constitutive exocytosis of both soluble cargo and LDCV membrane proteins, reducing the response to stimulation. We also observe increased basal release of both insulin and glucagon from pancreatic islet cells of mocha mice, suggesting a global disturbance in the release of peptide hormones. AP-3 exists as both ubiquitous and neuronal isoforms, but the analysis of mice lacking each of these isoforms individually and together shows that loss of both is required to reproduce the effect of the mocha mutation on the regulated pathway. In addition, we show that loss of the related adaptor protein AP-1 has a similar effect on regulated secretion but exacerbates the effect of AP-3 RNAi, suggesting distinct roles for the two adaptors in the regulated secretory pathway. The physiological action of peptide hormones and neural peptides depends on their sorting to vesicles capable of regulated exocytosis in response to stimulation. Despite the diversity and importance of signals released by this pathway, surprisingly little is understood about the molecular mechanisms involved in sorting to and indeed formation of the large dense core vesicles (LDCVs) that mediate regulated secretion as opposed to secretory vesicles that undergo constitutive release. We recently used RNA interference in cell lines to identify a requirement for the adaptor protein AP-3 in sorting to the regulated secretory pathway, but the importance of this role in vivo has remained unknown. Using mutant mice lacking various subunits of the AP-3 complex, we now show that AP-3 is indeed required for appropriate, regulated secretion in multiple neuroendocrine cell types. Although AP-3 exists as both ubiquitous and neuronal forms, we also find that either form alone suffices to confer regulated secretion. The results show that AP-3 plays a novel and essential role in regulating the release of peptide hormones and neural peptides.
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影响因子：
7.8
作者：
Janvier, Katy;Kato, Yukio;Boehm, Markus;Rose, Jeremy R;Martina, Jose A;Kim, Bong-Yoon;Venkatesan, Sundararajan;Bonifacino, Juan S
通讯作者：
Bonifacino, Juan S
影响因子：
4.5
作者：
Koegel, Tanja;Rudolf, Ruediger;Gerdes, Hans-Hermann
通讯作者：
Gerdes, Hans-Hermann
影响因子：
3.3
作者：
Burgess J;Jauregui M;Tan J;Rollins J;Lallet S;Leventis PA;Boulianne GL;Chang HC;Le Borgne R;Krämer H;Brill JA
通讯作者：
Brill JA
DOI：
10.1073/pnas.0509844103
发表时间：
2006-06-27
影响因子：
11.1
作者：
Grabner, Chad P.;Price, Steven D.;Fox, Aaron P.
通讯作者：
Fox, Aaron P.
影响因子：
64.5
作者：
Cool, DR;Normant, E;Loh, YP
通讯作者：
Loh, YP