Quantitative Proteomic Analysis of Small and Large Extracellular Vesicles (EVs) Reveals Enrichment of Adhesion Proteins in Small EVs
Quantitative Proteomic Analysis of Small and Large Extracellular Vesicles (EVs) Reveals Enrichment of Adhesion Proteins in Small EVs
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DOI：
10.1021/acs.jproteome.8b00647
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发表时间：
2019-03-01
影响因子：
4.4
通讯作者：
Weaver, Alissa M.
中科院分区：
文献类型：
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作者：
Jimenez, Lizandra;Yu, Hui;Weaver, Alissa M.
细胞外囊泡（EVs）是细胞间重要的通讯介质，因为它们的货物内容的蛋白质，脂质和rna。我们之前报道过称为外泌体的小ev （sev）促进定向和随机的细胞运动、侵袭和血清独立生长。相比之下，较大的ev （lev）在这些检测中没有活性，但可能具有独特的功能特性。为了鉴定可能对sev和lev的不同功能有贡献的蛋白质货物，我们对从结肠癌细胞系分离的ev使用了等压标签相对和绝对定量（iTRAQ）液相色谱（LC）串联质谱（MS）。生物信息学分析显示，sev富含与细胞连接、细胞基质粘附、外泌体生物发生机制和各种信号通路相关的蛋白质。相反，lev富含与核糖体和RNA生物发生、加工和代谢相关的蛋白质。对两种不同类型癌细胞纯化的ev进行Western blot分析，证实了sev中细胞基质和细胞粘附蛋白的富集。与这些数据一致，我们发现与相同蛋白质浓度的lev相比，细胞对sev涂层表面的粘附能力增强。这些数据表明sev的一个主要功能是促进细胞粘附。
Extracellular vesicles (EVs) are important mediators of cell cell communication due to their cargo content of proteins, lipids, and RNAs. We previously reported that small EVs (SEVs) called exosomes promote directed and random cell motility, invasion, and serum-independent growth. In contrast, larger EVs (LEVs) were not active in those assays, but might have unique functional properties. In order to identify protein cargos that may contribute to different functions of SEVs and LEVs, we used isobaric tags for relative and absolute quantitation (iTRAQ) liquid chromatography (LC) tandem mass spectrometry (MS) on EVs isolated from a colon cancer cell line. Bioinformatics analyses revealed that SEVs are enriched in proteins associated with cell cell junctions, cell matrix adhesion, exosome biogenesis machinery, and various signaling pathways. In contrast, LEVs are enriched in proteins associated with ribosome and RNA biogenesis, processing, and metabolism. Western blot analysis of EVs purified from two different cancer cell types confirmed the enrichment of cell matrix and cell cell adhesion proteins in SEVs. Consistent with those data, we found that cells exhibit enhanced adhesion to surfaces coated with SEVs compared to an equal protein concentration of LEVs. These data suggest that a major function of SEVs is to promote cellular adhesion.