Identification of LOV KELCH PROTEIN2 (LKP2)-interacting factors that can recruit LKP2 to nuclear bodies
Identification of LOV KELCH PROTEIN2 (LKP2)-interacting factors that can recruit LKP2 to nuclear bodies
复制标题
DOI：
10.1093/pcp/pci144
复制
发表时间：
2005-08-01
影响因子：
4.9
通讯作者：
Kiyosue, T
中科院分区：
文献类型：
--
作者：
Fukamatsu, Y;Mitsui, S;Kiyosue, T
LOV Kelch PROTEIN2(LKP2)是一种F-box蛋白，被认为在生物钟振荡器附近或中枢发挥作用。作为确定LKP2底物的第一步，以LKP2为诱饵进行了酵母双杂交筛选，分离出了两个相互作用因子Di19和Col1。瞬时表达的Di19-GUS融合蛋白定位于拟南芥叶柄细胞的细胞核中。Col 1等CO/Col家族蛋白也可与LKP1/ZTL、LKP2或FKF1相互作用。CO或CO1中的LKP2结合部位位于每种蛋白质的中心附近。CO或CO1中的CCT基序不足以与LKP2相互作用。LKP2通过F-box和kelch重复序列识别CO，而通过LOV结构域识别Col1。当LKP2与青色荧光蛋白(CFP)融合并在洋葱表皮细胞中瞬时表达时，CFP-LKP2信号定位于细胞核和胞浆。黄色荧光蛋白(YFP)-CO和YFP-COL1均位于细胞核内，瞬时表达时形成核小体。然而，CFP-LKP2与融合到CO或COL1的YFP共表达导致CFP-LKP2在核体中的募集。此外，CFP-LKP2和YFP-CO信号与Cajal小体的标志物pU2B‘’-MRFP信号共定位。这些结果表明，LKP2可能与核体中的CO/Col家族蛋白一起发挥功能。
LOV KELCH PROTEIN2 (LKP2) is an F-box protein that has been postulated to function centrally, or near to the circadian clock oscillator. As a first step to determine which proteins act as substrates of LKP2, yeast two-hybrid screening was performed using LKP2 as bait, and two interaction factors, Di19 and COL1, were isolated. The transiently expressed Di19-GUS fusion protein was localized in the nucleus of Arabidopsis petiole cells. COL1 and other CO/COL family proteins could also interact with LKP1/ZTL, LKP2 or FKF1. The LKP2-binding site in CO or COL1 was near the center of each protein. The CCT motif in CO or COL1 was not sufficient for interaction with LKP2. LKP2 recognized CO with F-box and kelch repeat-containing regions, while it recognized COL1 with an LOV domain. When LKP2 was fused with cyan fluorescent proein (CFP) and transiently expressed in onion epidermal cells, CFP-LKP2 signals were localized in the nucleus and cytosol. Both yellow fluorescent protein (YFP)-CO and YFP-COL1 were located in the nucleus, forming nuclear bodies when they were transiently expressed. However, co-expression of CFP-LKP2 with YFP fused to either CO or COL1 resulted in the recruitment of CFP-LKP2 in nuclear bodies. Furthermore, the CFP-LKP2 and YFP-CO signals co-localized with signals for pU2B''-mRFP, which is a marker for Cajal bodies. These results suggest the possibility that LKP2 functions with CO/COL family proteins in the nuclear bodies.