Stabilin-1 localizes to endosomes and the trans-Golgi network in human macrophages and interacts with GGA adaptors
Stabilin-1 localizes to endosomes and the trans-Golgi network in human macrophages and interacts with GGA adaptors
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DOI：
10.1189/jlb.0504300
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发表时间：
2004-12-01
影响因子：
5.5
通讯作者：
Goerdt, S
中科院分区：
文献类型：
--
作者：
Kzhyshkowska, J;Gratchev, A;Goerdt, S
Stabilin-1和stabilin-2构成了我们最近描述的一个新的含筋膜蛋白结构域透明质酸受体同源物家族。体内稳定素-1在窦状内皮细胞和巨噬细胞中表达，而稳定素-2在巨噬细胞中不表达。在本研究中，我们分析了稳定素-1在原代人巨噬细胞中的亚细胞分布。流式细胞术显示，稳定素-1在白细胞介素-4/地塞米松刺激的巨噬细胞（m2）表面表达。通过免疫荧光和共聚焦显微镜，我们确定了稳定蛋白-1优先定位于早期核内体抗原-1阳性的早期/分选核内体和通过转铁蛋白内吞噬鉴定的再循环核内体。稳定蛋白-1与p62 lck配体阳性的晚期内体和cd63阳性的溶酶体很少有关联，但与溶酶体相关的膜蛋白-1阳性溶酶体没有关联。在反式高尔基网络（TGN）中也发现了Stabilin-1，但在高尔基堆叠结构中没有发现。谷胱甘肽s -转移酶下拉试验显示，稳定蛋白1的细胞质尾部与最近发现的高尔基定位的，含γ耳的，腺苷5'-二磷酸核糖基化因子结合（GGA）接头GGA1， GGA2和GGA3长结合，介导高尔基体和内溶酶体/溶酶体间的运输。由于GGA3缺少Vps27p/Hrs/STAM结构域的一部分，Stabilin-1不与GGA3短结合。DDSLL和LL氨基酸基序的缺失导致稳定蛋白-1与GGAs结合减少。在MPhi2中，一小部分稳定蛋白-1与TGN中的GGA2和GGA3共定位。用brefeldin A处理导致TGN中稳定素-1的积累。我们的研究结果表明，稳定素-1参与了gga介导的生物合成和内体途径界面的分选过程；与其他gga相互作用蛋白类似，稳定蛋白-1可能在人巨噬细胞的内吞和分泌过程中发挥作用。
Stabilin-1 and stabilin-2 constitute a novel family of fasciclin domain-containing hyaluronan receptor homologues recently described by us. Whereas stabilin-1 is expressed in sinusoidal endothelial cells and in macrophages in vivo, stabilin-2 is absent from the latter. In the present study, we analyzed the subcellular distribution of stabilin-1 in primary human macrophages. Using flow cytometry, expression of stabilin-1 was demonstrated on the surface of interleukin-4/dexamethasone-stimulated macrophages (M 2). By immunofluorescense and confocal microscopy, we established that stabilin-1 is preferentially localized in early endosome antigen-1-positive early/sorting endosomes and in recycling endosomes identified by transferrin endocytosis. Association of stabilin-1 was infrequently seen with p62 lck ligand-positive late endosomes and with CD63-positive lysosomes but not in lysosome-associated membrane protein-1-positive lysosomes. Stabilin-1 was also found in the trans-Golgi network (TGN) but not in Golgi stack structures. Glutathione S-transferase pull-down assay revealed that the cytoplasmic tail of stabilin-1 but not stabilin-2 binds to recently discovered Golgi-localized, gamma-ear-containing, adenosine 5'-diphosphate-ribosylation factor-binding (GGA) adaptors GGA1, GGA2, and GGA3 long, mediating traffic between Golgi and endosomaI/lysosomal compartments. Stabilin-1 did not bind to GGA3 short, which lacks a part of the Vps27p/Hrs/STAM domain. Deletion of DDSLL and LL amino acid motifs resulted in decreased binding of stabilin-1 with GGAs. A small portion of stabilin-1 colocalized with GGA2 and GGA3 in the TGN in MPhi2. Treatment with brefeldin A resulted in accumulation of stabilin-1 in the TGN. Our results suggest that stabilin-1 is involved in the GGA-mediated sorting processes at the interface of the biosynthetic and endosomal pathways; similarly to other GGA-interacting proteins, stabilin-1 may thus function in endocytic and secretory processes of human macrophages.