The Drosophila homeodomain transcription factor, Vnd, associates with a variety of co-factors, is extensively phosphorylated and forms multiple complexes in embryos.
The Drosophila homeodomain transcription factor, Vnd, associates with a variety of co-factors, is extensively phosphorylated and forms multiple complexes in embryos.
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DOI：
10.1111/j.1742-4658.2008.06639.x
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发表时间：
2008-10
期刊：
影响因子：
--
通讯作者：
Mellerick DM
中科院分区：
文献类型：
--
作者：
Zhang H;Syu LJ;Modica V;Yu Z;Von Ohlen T;Mellerick DM
Vnd 是一种双转录调节因子，对于果蝇背腹模式至关重要。然而，我们对其调节活动的生化基础的理解是有限的。与 Vnd 在胚胎中抑制靶标表达的能力一致，内源表达的 Vnd 在果蝇 Kc167 细胞中与共抑制因子 Groucho 物理结合。 Vnd 在 Kc167 细胞中以单一复合物形式存在，而胚胎 Vnd 则形成多个高分子量复合物。与其脊椎动物同源物 Nkx2.2 不同，全长 Vnd 可以在 EMSA 中结合其靶标，这表明辅助因子的可用性可能会影响 Vnd 在瞬时转染中的弱调节活性。我们使用免疫共沉淀测定将 HMG1 型蛋白 D1 和新型 HLH 蛋白 Olig 鉴定为新型 Vnd 相互作用蛋白。此外，我们证明 D1 和 Olig 在果蝇胚胎发生过程中与 Vnd 共表达，这与这种相互作用的生物学基础一致。我们还认为 Vnd 的磷酸化状态影响其与辅助因子相互作用的能力，因为我们表明 Vnd 在胚胎中广泛磷酸化，并且它可以在体外被激活的 MAP 激酶磷酸化。这些结果凸显了 Vnd 介导的调节的复杂性。
Vnd is a dual transcriptional regulator that is essential for Drosophila dorsal-ventral patterning. Yet, our understanding of the biochemical basis for its regulatory activity is limited. Consistent with Vnd's ability to repress target expression in embryos, endogenously expressed Vnd physically associates with the co-repressor, Groucho, in Drosophila Kc167 cells. Vnd exists as a single complex in Kc167 cells in contrast to embryonic Vnd, which forms multiple high molecular weight complexes. Unlike its vertebrate homologue, Nkx2.2, full length Vnd can bind its target in EMSA, suggesting that co-factor availability may influence Vnd's weak regulatory activity in transient transfections. We identify the HMG1-type protein, D1, and the novel HLH protein, Olig, as novel Vnd-interacting proteins using co-immunoprecipitation assays. Furthermore, we demonstrate that both D1 and Olig are co-expressed with Vnd during Drosophila embryogenesis, consistent with a biological basis for this interaction. We also suggest that the phosphorylation state of Vnd influences its ability to interact with co-factors, because we show that Vnd is extensively phosphorylated in embryos and that it can be phosphorylated by activated MAP kinase in vitro. These results highlight the complexities of Vnd-mediated regulation.
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影响因子：
10.5
作者：
McDonald, JA;Holbrook, S;Mellerick, DM
通讯作者：
Mellerick, DM
影响因子：
64.5
作者：
ONEILL, EM;REBAY, I;RUBIN, GM
通讯作者：
RUBIN, GM
影响因子：
64.8
作者：
BRUNNER, D;DUCKER, K;KLAMBT, C
通讯作者：
KLAMBT, C
影响因子：
4.8
作者：
Phelps, DE;Dressler, GR
通讯作者：
Dressler, GR
影响因子：
4.8
作者：
Chin, MT;Pellacani, A;Lee, ME
通讯作者：
Lee, ME