dDYRK2 and Minibrain interact with the chromatin remodelling factors SNR1 and TRX
dDYRK2 and Minibrain interact with the chromatin remodelling factors SNR1 and TRX
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DOI：
10.1042/bj20060159
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发表时间：
2006-08-15
影响因子：
4.1
通讯作者：
Cleghon, Vaughn
中科院分区：
文献类型：
--
作者：
Kinstrie, Ross;Lochhead, Pamela A.;Cleghon, Vaughn
DYRK（双特异性酪氨酸磷酸化调节激酶）是一个保守的蛋白激酶家族，通过分子内机制将其激活环中的酪氨酸残基自磷酸化，并磷酸化丝氨酸/苏氨酸残基上的外源底物。关于 DYRK 家族成员及其结合伴侣的真正底物的身份知之甚少。为了解决这个问题，我们在果蝇胚胎 cDNA 文库的酵母双杂交筛选中使用全长 dDYRK2（果蝇 DYRK2）作为诱饵。在鉴定出的 14 个独立的 dDYRK2 相互作用克隆中，三个源自染色质重塑因子 SNR1（Snf5 相关 1），三个源自必需染色质成分 TRX（trithorax）。免疫共沉淀研究证实了 dDYRK2 与 SNR1 和 TRX 的关联。缺失分析表明 dDYRK2 的 C 末端调节与 SNR1 和 TRX 的相互作用。 DYRK 家族成员 MNB (Minibrain) 也被发现与 SNR1 和 TRX 共沉淀，这种关联不需要分子的 C 末端。还发现 dDYRK2 和 MNB 在体外和体内磷酸化 Thr(102) 位点的 SNR1。这种磷酸化需要 dDYRK2 高度保守的 DH-box（DYRK 同源盒），而 DH-box 对于 MNB 磷酸化来说并不是必需的。这是 SNR1 或其任何同源物磷酸化的第一个实例，表明 DYRK 激酶家族在染色质重塑中发挥作用。
The DYRKs (dual specificity tyrosine phosphorylation-regulated kinases) are a conserved family of protein kinases that autophosphorylate a tyrosine residue in their activation loop by an intramolecular mechanism and phosphorylate exogenous substrates on serine/threonine residues. Little is known about the identity of true substrates for DYRK family members and their binding partners. To address this question, we used full-length dDYRK2 (Drosophila DYRK2) as bait in a yeast two-hybrid screen of a Drosophila embryo cDNA library. Of 14 independent dDYRK2 interacting clones identified, three were derived from the chromatin remodelling factor, SNR1 (Snf5-related 1), and three from the essential chromatin component, TRX (trithorax). The association of dDYRK2 with SNR1 and TRX was confirmed by co-immunoprecipitation studies. Deletion analysis showed that the C-terminus of dDYRK2 modulated the interaction with SNR1 and TRX. DYRK family member MNB (Minibrain) was also found to co-precipitate with SNR1 and TRX, associations that did not require the C-terminus of the molecule. dDYRK2 and MNB were also found to phosphorylate SNR1 at Thr(102) in vitro and in vivo. This phosphorylation required the highly conserved DH-box (DYRK homology box) of dDYRK2, whereas the DH-box was not essential for phosphorylation by MNB. This is the first instance of phosphorylation of SNR1 or any of its homologues and implicates the DYRK family of kinases with a role in chromatin remodelling.