The ethylene-inducible PK12 kinase mediates the phosphorylation of SR splicing factors.
The ethylene-inducible PK12 kinase mediates the phosphorylation of SR splicing factors.
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DOI：
10.1046/j.1365-313x.2000.00657.x
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
S. Savaldi-Goldstein;G. Sessa;R. Fluhr
中科院分区：
文献类型：
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作者：
S. Savaldi-Goldstein;G. Sessa;R. Fluhr
烟草PK 12是由植物激素乙烯诱导的，并且是蛋白激酶的LAMMER家族的成员。该家族的成员在其C-末端含有一个独特的功能未知的“EHLAMMERI/VLGPLP”基序，并且与细胞周期蛋白和促分裂原活化蛋白（MAP）依赖性激酶相关。这个纲的动物成员在分化中起作用。它们在体内与富含丝氨酸/丝氨酸（SR）的剪接因子磷酸化并物理相互作用，以改变其活性和靶mRNA的剪接。最近在植物中描述了SR蛋白。通过激酶和结合测定法在体外测试PK 12 LAMMER激酶结合和磷酸化SR蛋白的能力。烟草PK 12磷酸化动物和植物SR蛋白，并与植物剪接因子atSRp 34/SR 1特异性相互作用。此外，通过定点诱变，发现LAMMER基序是PK 12激酶活性所需的，但不是底物结合所必需的。与剪接因子磷酸化的作用一致，发现PK 12在悬浮细胞中瞬时过表达时定位于细胞核。
The tobacco PK12 is induced by the plant hormone ethylene and is a member of the LAMMER family of protein kinases. Members of this family contain in their C-terminus a unique 'EHLAMMERI/VLGPLP' motif of unknown function, and are related to cyclin- and mitogen-activated protein (MAP)-dependent kinases. The animal members of this class play a role in differentiation. They phosphorylate and physically interact with serine/arginine-rich (SR) splicing factors in vivo to alter their activity and the splicing of target mRNAs. SR proteins have been recently described in plants. The capability of PK12 LAMMER kinase to bind and phosphorylate SR proteins was tested in vitro by kinase and binding assays. The tobacco PK12 phosphorylated both animal and plant SR proteins and specifically interacted with the plant splicing factor atSRp34/SR1. In addition, by site-directed mutagenesis, the LAMMER motif was found to be required for PK12 kinase activity but was not necessary for substrate binding. Consistent with a role in phosphorylation of splicing factors, PK12 was found to localize to the nucleus when transiently over-expressed in suspension cells.