ArfGAP3 regulates the transport of cation-independent mannose 6-phosphate receptor in the post-Golgi compartment.
ArfGAP3 regulates the transport of cation-independent mannose 6-phosphate receptor in the post-Golgi compartment.
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DOI：
10.1016/j.cub.2013.07.087
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发表时间：
2013-10-07
期刊：
影响因子：
--
通讯作者：
Randazzo PA
中科院分区：
文献类型：
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作者：
Shiba Y;Kametaka S;Waguri S;Presley JF;Randazzo PA
已知ArfGAP参与COPI运输中的货物分拣。然而，ArfGAP在后高尔基体膜交通中的作用尚未被定义。为了确定ArfGAP在后高尔基体交通中的功能，我们使用siRNA检查25个ArfGAP中的每一个对阳离子非依赖性甘露糖6-磷酸受体（CIMPR）定位的影响。我们发现ArfGAP 3的下调导致CIMPR的外周定位。该效应对ArfGAP 3是特异性的，并且依赖于其GAP活性，因为表型被ArfGAP 3拯救，而不是被ArfGAP 1、ArfGAP 2或ArfGAP 3的差距结构域突变体拯救。ArfGAP 3定位于trans-Golgi网络和早期内体。在ArfGAP 3表达减少的细胞中，组织蛋白酶D成熟减慢，其分泌加速。此外，从内源性CIMPR的内体到trans-Golgi网络的逆行运输，而不是缺乏管腔结构域的截短的CIMPR，在ArfGAP 3表达减少的细胞中受到干扰。此外，在ArfGAP 3表达减少的细胞中，表皮生长因子受体（EGFR）从早期内体的退出和EGF刺激后EGFR的降解减慢。ArfGAP 3与高尔基体定位的、含有γ-ear的ADP-核糖基化因子结合蛋白（GGA）缔合，并且ArfGAP 3敲低减少GGA的膜缔合。解释我们的结果的一个可能的机制是ArfGAP 3调节从早期内体到晚期内体的转运。我们提出了一个模型，其中ArfGAP 3调节高尔基体协会的GGA网格蛋白衔接子。
ArfGAPs are known to be involved in cargo sorting in COPI transport. However, the role of ArfGAPs in post-Golgi membrane traffic has not been defined. To determine the function of ArfGAPs in post-Golgi traffic, we used siRNA to examine each of 25 ArfGAPs for effects on cation-independent mannose 6-phosphate receptor (CIMPR) localization. We found that down-regulation of ArfGAP3 resulted in the peripheral localization of CIMPR. The effect was specific for ArfGAP3 and dependent on its GAP activity, because the phenotype was rescued by ArfGAP3 but not by ArfGAP1, ArfGAP2 or the GAP domain mutants of ArfGAP3. ArfGAP3 localized to the trans-Golgi network and early endosomes. In cells with reduced expression of ArfGAP3, Cathepsin D maturation was slowed and its secretion was accelerated. Also retrograde transport from the endosomes to the trans-Golgi network of endogenous CIMPR, but not truncated CIMPR lacking the luminal domain, was perturbed in cells with reduced expression of ArfGAP3. Furthermore the exit of epidermal growth factor receptor (EGFR) from the early endosomes and degradation of EGFR after EGF stimulation was slowed in cells with reduced expression of ArfGAP3. ArfGAP3 associates with Golgi-localized, γ-ear-containing, ADP-ribosylation factor binding proteins (GGAs), and ArfGAP3 knockdown reduces membrane association of GGAs. A possible mechanism explaining our results is that ArfGAP3 regulates transport from early endosomes to late endosomes. We suggest a model in which ArfGAP3 regulates Golgi association of GGA clathrin adaptors.