hnRNP-K and Purα act together to repress the transcriptional activity of the CD43 gene promoter
hnRNP-K and Purα act together to repress the transcriptional activity of the CD43 gene promoter
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DOI：
10.1182/blood.v100.10.3536
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发表时间：
2002-11-15
期刊：
影响因子：
20.3
通讯作者：
Shelley, CS
中科院分区：
文献类型：
--
作者：
Da Silva, N;Bharti, A;Shelley, CS
CD43 是一种丰富的、高度糖基化的分子，专门在白细胞和血小板表面表达。当白细胞处于静止状态时，CD43 会起到防止同型和异型相互作用的作用。然而，在白细胞激活过程中，CD43 表达受到抑制，从而促进趋化、吞噬、聚集、内皮粘附和跨内皮迁移所需的细胞间接触。因此，CD43 抑制在先天免疫和获得性免疫中都起着至关重要的作用。在这里，我们报告在白细胞系 K562 激活期间发生 CD43 mRNA 水平的急剧下调。这种抑制与 CD43 基因启动子转录活性的抑制同时发生。我们已经确定，异质核核糖核蛋白 K (hnRNP-K) 和 Puralpha 共同作用，在 K562 激活过程中介导 CD43 启动子的抑制。 hnRNP-K 分子和 Pura 结合单链 DNA。因此，CD43 启动子内单链结构的暴露可能在影响 CD43 抑制中发挥重要作用。
CD43 is an abundant, heavily glycosylated molecule expressed specifically on the surface of leukocytes and platelets. When leukocytes are at rest, CD43 acts to prevent both homotypic and heterotypic Interactions. However, during leukocyte activation CD43 expression is repressed, facilitating the intercellular contact required for chemotaxis, phagocytosis, aggregation, adhesion to endothelium, and transendothelial migration. Consequently, CD43 repression plays a vital role both in Innate and acquired immunity. Here we report that a dramatic down-regulation of CD43 mRNA levels occurs during activation of the leukocytic cell line K562. This repression coincides with repression of the transcriptional activity of the CD43 gene promoter. We have determined that heterogeneous nuclear ribonucleoprotein K (hnRNP-K) and Puralpha act together to mediate repression of the CD43 promoter during K562 activation. The hnRNP-K molecule and Pura bind single-stranded DNA. Therefore, exposure of single-stranded structures within the CD43 promoter probably plays a major role in effecting CD43 repression.