Erythropoietin receptor signaling is membrane raft dependent.
Erythropoietin receptor signaling is membrane raft dependent.
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DOI：
10.1371/journal.pone.0034477
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
List AF
中科院分区：
文献类型：
--
作者：
McGraw KL;Fuhler GM;Johnson JO;Clark JA;Caceres GC;Sokol L;List AF
在促红细胞生成素（Epo）接合后，Epo-受体（R）同型二聚化以激活JAK 2和林恩，其磷酸化STAT 5。虽然最近的研究已经确定了关键的负调控Epo-R信号，很少有人知道的作用，膜定位在控制受体信号的保真度。在这里，我们展示了膜筏（MR）微区在创建Epo-R信号传导所必需的离散信号平台中的关键作用。用Epo处理UT 7细胞诱导MR组装和聚结。共聚焦显微镜显示，在Epo刺激后，筏聚集体显著增加（平均值，4.3±1.4（SE）对25.6±3.2聚集体/细胞; p≤0.001），伴随着簇大小增加>3倍（p≤0.001）。筏部分免疫印迹显示Epo刺激后Epo-R易位到MR，并通过Epo刺激的UT 7细胞和初级红细胞爆发中的荧光显微镜证实。受体募集到MR中伴随着JAK 2、林恩和STAT 5及其活化形式的掺入。筏破坏胆固醇耗竭熄灭Epo诱导Jak 2，STAT 5，Akt和MAPK磷酸化在UT 7细胞和红系祖细胞。此外，Rho GTP酶Rac 1或RhoA的抑制阻断了受体募集到筏组分中，表明这些GTP酶在受体运输中的作用。这些数据确立了MR在Epo-R和信号中间体招募和组装成离散膜信号单元中的关键作用。
Upon erythropoietin (Epo) engagement, Epo-receptor (R) homodimerizes to activate JAK2 and Lyn, which phosphorylate STAT5. Although recent investigations have identified key negative regulators of Epo-R signaling, little is known about the role of membrane localization in controlling receptor signal fidelity. Here we show a critical role for membrane raft (MR) microdomains in creation of discrete signaling platforms essential for Epo-R signaling. Treatment of UT7 cells with Epo induced MR assembly and coalescence. Confocal microscopy showed that raft aggregates significantly increased after Epo stimulation (mean, 4.3±1.4(SE) vs. 25.6±3.2 aggregates/cell; p≤0.001), accompanied by a >3-fold increase in cluster size (p≤0.001). Raft fraction immunoblotting showed Epo-R translocation to MR after Epo stimulation and was confirmed by fluorescence microscopy in Epo stimulated UT7 cells and primary erythroid bursts. Receptor recruitment into MR was accompanied by incorporation of JAK2, Lyn, and STAT5 and their activated forms. Raft disruption by cholesterol depletion extinguished Epo induced Jak2, STAT5, Akt and MAPK phosphorylation in UT7 cells and erythroid progenitors. Furthermore, inhibition of the Rho GTPases Rac1 or RhoA blocked receptor recruitment into raft fractions, indicating a role for these GTPases in receptor trafficking. These data establish a critical role for MR in recruitment and assembly of Epo-R and signal intermediates into discrete membrane signaling units.
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影响因子：
20.3
作者：
Hoefsloot, LH;vanAmelsvoort, MP;Lowenberg, B
通讯作者：
Lowenberg, B
影响因子：
20.3
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Bellamy, WT;Richter, L;List, AF
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List, AF
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Wojchowski, Don M.
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作者：
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通讯作者：
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影响因子：
3.5
作者：
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通讯作者：
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