Upstream stimulatory factors stimulate transcription through E-box motifs in the PF4 gene in megakaryocytes
Upstream stimulatory factors stimulate transcription through E-box motifs in the PF4 gene in megakaryocytes
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DOI：
10.1182/blood-2003-09-3107
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发表时间：
2004-10-01
期刊：
影响因子：
20.3
通讯作者：
Doi, T
中科院分区：
文献类型：
--
作者：
Okada, Y;Matsuura, E;Doi, T
血小板因子4（PF 4）在巨核细胞分化过程中表达。我们以前证明了同源结构域蛋白（髓细胞亲合整合位点1 [MEIS 1]，Pbx调节蛋白1 [PREP 1]和前B细胞白血病转录因子[PBX]）结合MEIS 1结合元件[TME]的新型调节元件串联重复序列，并反式激活大鼠PF 4启动子。在本研究中，我们调查和鉴定巨核细胞HEL细胞中的其他TME结合蛋白质使用质谱。在已鉴定的蛋白质中，我们重点研究了上游刺激因子（USF 1）和USF 2，并研究了它们对PF 4启动子的影响。USF 1和2与TME中的E-box基序结合，并强烈反式激活PF 4启动子。此外，通过染色质免疫沉淀（ChIP）试验证明了USF 1和2与大鼠巨核细胞中TME的生理结合。有趣的是，TME中的E-box基序在人和小鼠PF 4启动子的TME样序列中是保守的。USF 1和2也结合到人TME样序列并反式激活人PF 4启动子。逆转录聚合酶链反应（RT-PCR）检测人CD 34（+）细胞来源的巨核细胞中USF 1和USF 2的表达。因此，这些研究表明，新的TME结合转录因子，USF 1和2，反式激活大鼠和人类PF 4启动子，并可能在巨核细胞基因表达中发挥重要作用。(C)2004年，美国血液学会。
Platelet factor 4 (PF4) is expressed during megakaryocytic differentiation. We previously demonstrated that the homeodomain proteins (myeloid ecotropic integration site 1 [MEIS1], Pbx-regulating protein 1 [PREP1], and pre-B-cell leukemia transcription factors [PBXs]) bind to the novel regulatory element tandem repeat of MEIS1 binding element [TME] and transactivate the rat PF4 promoter. In the present study, we investigated and identified other TME binding proteins in megakaryocytic HEL cells using mass spectrometry. Among identified proteins, we focused on upstream stimulatory factor (USF1) and USF2 and investigated their effects on the PF4 promoter. USF1 and 2 bound to the E-box motif in the TME and strongly transactivated the PF4 promoter. Furthermore, physiologic bindings of USF1 and 2 to the TME in rat megakaryocytes were demonstrated by the chromatin immunoprecipitation (ChIP) assay. Interestingly, the E-box motif in the TME was conserved in TME-like sequences of both the human and mouse PF4 promoters. USF1 and 2 also bound to the human TME-like sequence and transactivated the human PF4 promoter. Expressions of USF1 and 2 were detected by reverse-transcriptase-polymerase chain reaction (RT-PCR) in the human megakaryocytes derived from CD34(+) cells. Thus, these studies demonstrate that the novel TME binding transcription factors, USF1 and 2, transactivate rat and human PF4 promoters and may play an important role in megakaryocytic gene expression. (C) 2004 by The American Society of Hematology.