Macrophage Receptor with Collagenous Structure (MARCO) Is Processed by either Macropinocytosis or Endocytosis-Autophagy Pathway.
Macrophage Receptor with Collagenous Structure (MARCO) Is Processed by either Macropinocytosis or Endocytosis-Autophagy Pathway.
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DOI：
10.1371/journal.pone.0142062
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Kanno S
中科院分区：
文献类型：
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作者：
Hirano S;Kanno S
具有胶原结构的巨噬细胞受体（MARCO）蛋白是吞噬细胞上未调理或环境颗粒的质膜受体。在这里，我们表明，MARCO被内化的质膜皱紧接着巨胞饮作用或内吞作用，然后与自噬体在CHO-K1细胞稳定转染GFP-MARCO融合。当质膜下沉时，巨胞饮过程产生大的囊泡。内吞作用/自噬体（两性体）产生小的荧光斑点，在谷氨酰胺、氯喹、巴弗洛霉素、氨和其他胺的存在下可见。小斑点，但不是大泡，与LC 3B和溶酶体共定位。LC 3-II/LC 3-I比率在谷氨酰胺、氨和氯喹存在下在各种细胞中增加。小斑点以2-3 μm/sec的速度在核周区和细胞远端之间来回运输;微管蛋白而不是肌动蛋白调节小斑点的运输。MARCO是一种粘附性质膜受体，除吞噬作用外，还可通过巨胞饮和内吞途径将各种细胞外物质掺入细胞内。
The Macrophage Receptor with COllagenous structure (MARCO) protein is a plasma membrane receptor for un-opsonized or environmental particles on phagocytic cells. Here, we show that MARCO was internalized either by ruffling of plasma membrane followed by macropinocytosis or by endocytosis followed by fusion with autophagosome in CHO-K1 cells stably transfected with GFP-MARCO. The macropinocytic process generated large vesicles when the plasma membrane subsided. The endocytosis/autophagosome (amphisome) generated small fluorescent puncta which were visible in the presence of glutamine, chloroquine, bafilomycin, ammonia, and other amines. The small puncta, but not the large vesicles, co-localized with LC3B and lysosomes. The LC3-II/LC3-I ratio increased in the presence of glutamine, ammonia, and chloroquine in various cells. The small puncta trafficked between the peri-nuclear region and the distal ends of cells back and forth at rates of up to 2–3 μm/sec; tubulin, but not actin, regulated the trafficking of the small puncta. Besides phagocytosis MARCO, an adhesive plasma membrane receptor, may play a role in incorporation of various extracellular materials into the cell via both macropinocytic and endocytic pathways.