An arrestin-dependent multi-kinase signaling complex mediates MIP-1β/CCL4 signaling and chemotaxis of primary human macrophages
An arrestin-dependent multi-kinase signaling complex mediates MIP-1β/CCL4 signaling and chemotaxis of primary human macrophages
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DOI：
10.1189/jlb.0908551
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发表时间：
2009-10-01
影响因子：
5.5
通讯作者：
Collman, Ronald G.
中科院分区：
文献类型：
--
作者：
Cheung, Ricky;Malik, Mobeen;Collman, Ronald G.
MIP-1 β /CCL4是巨噬细胞迁移和通过CCR5信号的主要调节因子。巨噬细胞中有几种蛋白激酶与CCR5相关，包括src激酶Lyn、PI3K、局灶黏附相关激酶Pyk2和MAPK家族成员，但这些激酶是否以及如何调节巨噬细胞趋化性尚不清楚。为了确定这些信号分子的作用，我们研究了内源性蛋白在原代人巨噬细胞中的功能和相互作用。通过siRNA基因沉默和药物抑制，我们发现MIP-1 β对CCR5刺激的趋化反应需要激活Pyk2、PI3K、p85和Lyn以及MAPK ERK。CCR5的MIP-1 β激活触发细胞质中Pyk2和PI3K p85的易位，与Lyn在质膜上共定位，形成多分子复合物。我们进一步表明，阻滞蛋白被招募到复合物中，抑制蛋白下调会损害复合物的形成和巨噬细胞对MIP-1 β的趋化性。总之，这些结果确定了趋化因子受体调节趋化性的新机制，并表明在生物学上重要的原代人类细胞类型中，阻滞蛋白可能作为连接CCR5和多种下游信号分子的支架蛋白。j . Leukoc。生物学报。86:833-845；2009.
MIP-1 beta/CCL4 is a principal regulator of macrophage migration and signals through CCR5. Several protein kinases are linked to CCR5 in macrophages including the src kinase Lyn, PI3K, focal adhesion related kinase Pyk2, and members of the MAPK family, but whether and how these kinases regulate macrophage chemotaxis are not known. To define the role of these signaling molecules, we examined the functions and interactions of endogenous proteins in primary human macrophages. Using siRNA gene silencing and pharmacologic inhibition, we show that chemotaxis in response to CCR5 stimulation by MIP-1 beta requires activation of Pyk2, PI3K p85, and Lyn, as well as MAPK ERK. MIP-1 beta activation of CCR5 triggered translocation of Pyk2 and PI3K p85 from the cytoplasm to colocalize with Lyn at the plasma membrane with formation of a multimolecular complex. We show further that arrestins were recruited into the complex, and arrestin down-regulation impaired complex formation and macrophage chemotaxis toward MIP-1 beta. Together, these results identify a novel mechanism of chemokine receptor regulation of chemotaxis and suggest that arrestins may serve as scaffolding proteins linking CCR5 to multiple downstream signaling molecules in a biologically important primary human cell type. J. Leukoc. Biol. 86: 833-845; 2009.