Regulation of the Ets-1 transcription factor by sumoylation and ubiquitinylation
Regulation of the Ets-1 transcription factor by sumoylation and ubiquitinylation
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DOI：
10.1038/sj.onc.1209789
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发表时间：
2007-01-01
期刊：
影响因子：
8
通讯作者：
Fafeur, V.
中科院分区：
文献类型：
--
作者：
Ji, Z.;Degerny, C.;Fafeur, V.
苏酰化和泛素化通过共价连接到靶蛋白的赖氨酸残基上可逆地调节转录因子的活性。我们检查了 Ets-1 转录因子是否通过苏酰化和/或泛素化进行修饰。在 Ets-1 的四个潜在 SUMO 基序中，我们鉴定了 (LKYE)-Y-15 和 IK(227)QE 基序内的赖氨酸 15 和 227，作为 SUMO 化受体位点。通过转染 Ets-1 野生型 (WT) 或其苏木化缺陷版本 (Ets-1 K15R/K227R)，以及 WT 或 SUMO 途径的突变蛋白，我们进一步证明 E2 SUMO 结合酶 Ubc9 和 E3 SUMO 连接酶 PIASy 可以增强 Ets-1 苏木化，而 SUMO 蛋白酶 SENP1 可以去苏木化Ets-1。我们还发现Ets-1被K48连接的多泛素化修饰，与SUMO化受体位点无关，并通过26S蛋白酶体途径降解，而Ets-1的SUMO化并不影响其稳定性。最后，Ets-1 的苏酰化导致反式激活减少，我们证明之前在协同控制基序中鉴定的关键赖氨酸残基是 Ets-1 的苏酰化受体位点。这些数据表明Ets-1可以通过SUMO化和/或泛素化进行修饰，SUMO化抑制Ets-1的转录活性并且对泛素-蛋白酶体降解途径没有明显的拮抗作用。
Sumoylation and ubiquitinylation reversibly regulate the activity of transcription factors through covalent attachment to lysine residues of target proteins. We examined whether the Ets-1 transcription factor is modified by sumoylation and/or ubiquitinylation. Among four potential SUMO motifs in Ets-1, we identified lysines 15 and 227 within the (LKYE)-Y-15 and IK(227)QE motifs, as being the sumoylation acceptor sites. Using transfection of Ets-1 wildtype (WT) or its sumoylation deficient version (Ets-1 K15R/K227R), as well as WT or mutant proteins of the SUMO pathway, we further demonstrated that the E2 SUMO-conjugating enzyme Ubc9 and a E3 SUMO ligase, PIASy, can enhance Ets-1 sumoylation, while a SUMO protease, SENP1, can desumoylate Ets-1. We also found that Ets-1 is modified by K48-linked polyubiquitinylation independently of the sumoylation acceptor sites and is degraded through the 26S proteasome pathway, while sumoylation of Ets-1 does not affect its stability. Finally, sumoylation of Ets-1 leads to reduced transactivation and we demonstrated that previously identified critical lysine residues in Synergistic Control motifs are the sumoylation acceptor sites of Ets-1. These data show that Ets-1 can be modified by sumoylation and/or ubiquitinylation, with sumoylation repressing transcriptional activity of Ets-1 and having no clear antagonistic action on the ubiquitin-proteasome degradation pathway.