CD109 is a component of exosome secreted from cultured cells
CD109 is a component of exosome secreted from cultured cells
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CD109 是培养细胞分泌的外泌体的组成部分
DOI：
10.1016/j.bbrc.2015.12.063
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发表时间：
2016
影响因子：
3.1
通讯作者：
Murakumo Y
中科院分区：
文献类型：
--
作者：
Sakakura H;Mii S;Hagiwara S;Kato T;Yamamoto N;Hibi H;Takahashi M;Murakumo Y
外来体是从各种类型的细胞释放的50 - 100 nm直径的膜囊泡。外泌体保留蛋白质、mRNA和miRNA，它们可以被运输到周围细胞。CD109是一种糖基磷脂酰肌醇锚定的糖蛋白，在体外从细胞表面释放到培养基中。最近，有报道称，从细胞表面分泌的CD109下调人角质形成细胞中的转化生长因子-β信号传导。在这项研究中，我们发现，CD109是条件培养基中的外泌体的组分。用抗FLAG亲和凝胶免疫沉淀从表达FLAG-CD109（293/FLAG-CD109）的HEK293细胞分泌的条件培养基中的FLAG标记的人CD109（FLAG-CD109），并通过质谱和蛋白质印迹分析共沉淀的蛋白质。外泌体蛋白与CD109相关。我们揭示了来自293/FLAG-CD 109的条件培养基的外来体组分中CD 109的存在。此外，使用免疫电子显微镜证实了CD109在外泌体中的定位。当我们使用表达FLAG标记的截短的CD109（其不含C末端区域）的HEK293细胞时，在条件培养基中未检测到截短的CD109与外泌体的缔合。这些发现表明，CD109是一种外泌体蛋白，并且CD109的C-末端区域是其存在于外泌体中所必需的。
Exosomes are 50–100-nm-diameter membrane vesicles released from various types of cells. Exosomes retain proteins, mRNAs and miRNAs, which can be transported to surrounding cells. CD109 is a glycosylphosphatidylinositol-anchored glycoprotein, and is released from the cell surface to the culture mediumin vitro. Recently, it was reported that secreted CD109 from the cell surface downregulates transforming growth factor-β signaling in human keratinocytes. In this study, we revealed that CD109 is a component of the exosome in conditioned medium. FLAG-tagged human CD109 (FLAG-CD109) in conditioned medium secreted from HEK293 cells expressing FLAG-CD109 (293/FLAG-CD109) was immunoprecipitated with anti-FLAG affinity gel, and the co-precipitated proteins were analyzed by mass spectrometry and western blotting. Exosomal proteins were associated with CD109. We revealed the presence of CD109 in exosome fractions from conditioned medium of 293/FLAG-CD109. Moreover, the localization of CD109 in the exosome was demonstrated using immuno-electron microscopy. When we used HEK293 cells expressing FLAG-tagged truncated CD109, which does not contain the C-terminal region, the association of truncated CD109 with exosomes was not detected in conditioned medium. These findings indicate that CD109 is an exosomal protein and that the C-terminal region of CD109 is required for its presence in the exosome.