Ligand-dependent reduction in the membrane mobility of FLAGELLIN SENSITIVE2, an Arabidopsis receptor-like kinase
Ligand-dependent reduction in the membrane mobility of FLAGELLIN SENSITIVE2, an Arabidopsis receptor-like kinase
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DOI：
10.1093/pcp/pcm132
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发表时间：
2007-11-01
影响因子：
4.9
通讯作者：
Reddy, A. S. N.
中科院分区：
文献类型：
--
作者：
Ali, Gul Shad;Prasad, K. V. S. K.;Reddy, A. S. N.
拟南芥鞭毛蛋白敏感蛋白2（FLS 2）是一种跨膜的富含亮氨酸重复序列的受体样激酶，它识别细菌鞭毛蛋白的一个保守的22个氨基酸肽（flg 22），激活下游防御信号通路，从而增强植物对病原菌的抗性。然而，在细胞膜中激活FLS 2的潜在机制尚未完全了解。利用光漂白后的荧光恢复（FRAP），我们证明了质膜中大约75的FLS 2横向扩散，扩散系数为0.34 μ m（2）s（-1），表明它移动迅速。此外，我们表明，FLS 2是移动的在flg 22的存在下，这表明其配体依赖性的限制微域或与其他不太移动的膜蛋白的瞬时相互作用。使用在体内的双分子荧光互补（BiFC）系统和荧光共振能量转移（FRET），这揭示了在体内蛋白质蛋白质的相互作用，我们表明，FLS 2不homodimerize无论是组成型或flg 22的存在下。我们的数据表明，结合flg 22后FLS 2的流动性降低及其以单体形式存在是FLS 2早期信号传导的重要机制特征。
Arabidopsis Flagellin sensitive2 (FLS2) is a transmembrane leucine-rich repeat receptor-like kinase, which recognizes a conserved 22 amino acid peptide (flg22) of bacterial flagellin and activates downstream defense signaling pathways resulting in enhanced resistance against plant pathogens. The underlying mechanisms for the activation of FLS2 in the cell membrane, however, are not fully understood. Using fluorescence recovery after photobleaching (FRAP), we demonstrate that approximately 75 of the FLS2 in the plasma membrane diffuses laterally with a diffusion coefficient of 0.34 mu m(2) s(-1), indicating that it moves rapidly. Further, we show that FLS2 is less mobile in the presence of flg22, suggesting its ligand-dependent confinement to microdomains or transient interaction with other less mobile membrane proteins. Using an in vivo bimolecular fluorescence complementation (BiFC) system and fluorescence resonance energy transfer (FRET), which reveals in vivo proteinprotein interactions, we show that FLS2 does not homodimerize either constitutively or in the presence of flg22. Our data suggest that the reduced mobility of FLS2 after binding flg22 and its existence in monomeric form are important mechanistic features of FLS2 early signaling.