Mesencephalic Astrocyte-derived Neurotrophic Factor (MANF) Secretion and Cell Surface Binding Are Modulated by KDEL Receptors
Mesencephalic Astrocyte-derived Neurotrophic Factor (MANF) Secretion and Cell Surface Binding Are Modulated by KDEL Receptors
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DOI：
10.1074/jbc.m112.400648
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发表时间：
2013-02-08
影响因子：
4.8
通讯作者：
Harvey, Brandon K.
中科院分区：
文献类型：
--
作者：
Henderson, Mark J.;Richie, Christopher T.;Harvey, Brandon K.
中脑星形胶质细胞源性神经营养因子（MANF）是一种内质网应激反应蛋白，在神经变性动物模型中具有神经保护作用，但其潜在机制尚不清楚。我们构建了一组含有或缺乏高度保守的MANF的最后四个氨基酸（“RTDL”）的慢病毒载体，类似于典型的内质网保留信号（“KDEL”），以研究MANF在神经母细胞瘤细胞和大鼠初级皮层神经元中的调节。RTDL序列是内质网保留和内质网应激分泌反应所必需的。过表达KDEL受体类似物（KDELRs）会显著减少MANF分泌，但对缺乏RTDL的MANF没有影响。MANF与质膜的结合也需要RTDL序列，并被一种已知与KDELRs相互作用的肽抑制，这表明MANF在表面与KDELRs结合。我们检测到flag标记的kdelr的表面定位，其水平在内质网应激后增加。我们的研究为MANF运输的调控提供了新的见解，并对其他含有kdel样保留信号的分泌蛋白具有启示意义。
Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER) stress-responsive protein with neuroprotective effects in animal models of neuro-degeneration, but the underlying mechanism is not understood. We constructed a set of lentiviral vectors that contain or lack the highly conserved final four amino acids of MANF ("RTDL"), which resemble the canonical ER retention signal ("KDEL"), to study MANF regulation in neuroblastoma cells and rat primary cortical neurons. The RTDL sequence was required for both ER retention and secretory response to ER stress. Overexpression of KDEL receptor paralogs (KDELRs) differentially reduced MANF secretion but had no effect on MANF lacking RTDL. MANF binding to the plasma membrane also required the RTDL sequence and was inhibited with a peptide known to interact with KDELRs, suggesting MANF binds KDELRs at the surface. We detected surface localization of FLAG-tagged KDELRs, with levels increasing following ER stress. Our study provides new insight into the regulation of MANF trafficking and has implications for other secreted proteins containing a KDEL-like retention signal.