Department of Biochemistry, Nencki Institute of Experimental Biology, Warsaw, Poland.
Biochem Biophys Res Commun. 2011 Sep 9;412(4):683-7. doi: 10.1016/j.bbrc.2011.08.025. Epub 2011 Aug 16.
Matrix vesicles (MVs) are cell-derived membranous entities crucial for mineral formation in the extracellular matrix. One of the dominant groups of constitutive proteins present in MVs, recognised as regulators of mineralization in norm and pathology, are annexins. In this report, besides the annexins already described (AnxA2 and AnxA6), we identified AnxA1 and AnxA7, but not AnxA4, to become selectively enriched in MVs of Saos-2 cells upon stimulation for mineralization. Among them, AnxA6 was found to be almost EGTA-non extractable from matrix vesicles. Moreover, our report provides the first evidence of annexin-binding S100 proteins to be present in MVs of mineralizing cells. We observed that S100A10 and S100A6, but not S100A11, were selectively translocated to the MVs of Saos-2 cells upon mineralization. This observation provides the rationale for more detailed studies on the role of annexin-S100 interactions in MV-mediated mineralization.
基质小泡 (MVs) 是细胞来源的膜性实体，对于细胞外基质中矿物质的形成至关重要。MVs 中存在的一组主要的组成型蛋白质被认为是正常和病理条件下矿物质形成的调节剂，即膜联蛋白。在本报告中，除了已经描述的膜联蛋白（AnxA2 和 AnxA6）外，我们还鉴定出 AnxA1 和 AnxA7，但不是 AnxA4，在 Saos-2 细胞矿化刺激下，这些蛋白选择性地富集在基质小泡中。其中，AnxA6 几乎不能从基质小泡中用 EGTA 提取。此外，本报告首次提供了证据表明，结合 S100 蛋白的膜联蛋白存在于矿化细胞的基质小泡中。我们观察到，S100A10 和 S100A6，但不是 S100A11，在 Saos-2 细胞矿化时选择性地转位到基质小泡中。这一观察结果为进一步研究膜联蛋白-S100 相互作用在 MV 介导的矿化中的作用提供了依据。
