Characterization of a new family of protein kinases from Arabidopsis containing phosphoinositide 3/4-kinase and ubiquitin-like domains
Characterization of a new family of protein kinases from Arabidopsis containing phosphoinositide 3/4-kinase and ubiquitin-like domains
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DOI：
10.1042/bj20070959
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发表时间：
2008-01-01
影响因子：
4.1
通讯作者：
Boss, Wendy F.
中科院分区：
文献类型：
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作者：
Galvao, Rafaelo M.;Kota, Uma;Boss, Wendy F.
拟南芥（拟南芥）中至少有两个预计编码 II 型 PI4K（磷酸肌醇 4 激酶）的基因，即 AtPI4K gamma 4 和 AtPI4K gamma 7，编码的酶具有与 PIKK（磷酸肌醇激酶相关激酶）家族成员相似的催化特性。 AtPI4K gamma 4 和 AtPI4K gamma 7 发生自磷酸化并使蛋白质底物的丝氨酸/苏氨酸残基磷酸化，但没有可检测到的脂质激酶活性。 AtPI4K gamma 4 和 AtPI4K gamma 7 是包含 N 末端 UBL（泛素样）结构域的五个假定 AtPI4K 子集的成员。 AtPI4K gamma 4 的体外分析表明，它直接与参与泛素蛋白酶体系统的两种蛋白质（即 UFD1（泛素融合降解 1）和 RPN10（调节颗粒非 ATP 酶 10））相互作用并磷酸化。根据目前的结果，我们建议AtPI4K gamma 4和AtPI4K gamma 7应指定为UbDK gamma 4和UbDK gamma 7（（u）在bar biquitin-like下（d）在bar omain下（k）在bar inases gamma 4和gamma 7下）。这些含有 UBL 结构域的 AtPI4K 对应于蛋白激酶的新 PIKK 亚家族。此外，UFD1 和 RPN10 磷酸化代表了一种可以调节其功能的额外机制。
At least two of the genes predicted to encode type II PI4K (phosphoinositide 4-kinase) in Arabidopsis thaliana (thale cress), namely AtPI4K gamma 4 and AtPI4K gamma 7, encode enzymes with catalytic properties similar to those of members of the PIKK (phosphoinositide kinase-related kinase) family. AtPI4K gamma 4 and AtPI4K gamma 7 undergo autophosphorylation and phosphorylate serine/threonine residues of protein substrates, but have no detectable lipid kinase activity. AtPI4K gamma 4 and AtPI4K gamma 7 are members of a subset of five putative AtPI4Ks that contain N-terminal UBL (ubiquitin-like) domains. In vitro analysis of AtPI4K gamma 4 indicates that it interacts directly with, and phosphorylates, two proteins involved in the ubiquitin-proteasome system, namely UFD1 (ubiquitin fusion degradation 1) and RPN10 (regulatory particle non-ATPase 10). On the basis of the present results, we propose that AtPI4K gamma 4 and AtPI4K gamma 7 should be designated UbDK gamma 4 and UbDK gamma 7 ((u) under bar biquitin-like (d) under bar omain (k) under bar inases gamma 4 and gamma 7). These UBL-domain-containing AtPI4Ks correspond to a new PIKK subfamily of protein kinases. Furthermore, UFD1 and RPN10 phosphorylation represents an additional mechanism by which their function can be regulated.