Interactions between plant RING-H2 and plant-specific NAC (NAM/ATAF1/2/CUC2) proteins:: RING-H2 molecular specificity and cellular localization
Interactions between plant RING-H2 and plant-specific NAC (NAM/ATAF1/2/CUC2) proteins:: RING-H2 molecular specificity and cellular localization
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DOI：
10.1042/bj20021123
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发表时间：
2003-04-01
影响因子：
4.1
通讯作者：
Skriver, K
中科院分区：
文献类型：
--
作者：
Greve, K;La Cour, T;Skriver, K
在模式植物拟南芥（塔勒水芹）中发现了许多高度保守的RING-H2结构域。为了表征潜在的RING-H2蛋白相互作用，将小RING-H2蛋白RHA 2a用作酵母双杂交筛选中的诱饵。RHA 2a与植物特异性NAC [NAM（“无顶端分生组织”）、ATAF 1/2、CUC 2（“杯状子叶2”）]转录因子之一相互作用，在此称为ANAC（脱落酸响应性NAC）。核心RING-H2结构域足以进行相互作用。然后检查了11个结构不同的RING-H2结构域与ANAC相互作用的能力。检测到三个结构域的强大的相互作用，表明相互作用的多特异性。与ANAC相互作用的结构域在对应于许多RING-H2结构域中的脯氨酸的位置处含有谷氨酸残基。在RHA 2a中将该谷氨酸残基转化为脯氨酸降低了其与ANAC相互作用的能力，最有可能是通过改变相互作用表面。这表明RING-H2结构域中的短的发散区域调节相互作用特异性。ANAC含有一个简并的二分核定位信号（NLS），而RHG 1a，也被确定为ANAC相互作用伴侣，含有一个基本的NLS。两种信号均将β-葡萄糖醛酸酶报告基因融合定位于细胞核。N-末端截短的RHA 2a还指导核定位，显然依赖于RING-H2结构域中的碱性氨基酸。RING-H2蛋白和ANAC的核共定位可以使它们在体内相互作用以调节ANAC转录因子的活性。
Numerous, highly conserved RING-H2 domains are found in the model plant Arabidopsis thaliana (thale cress). To characterize potential RING-H2 protein interactions, the small RING-H2 protein RHA2a was used as bait in a yeast two-hybrid screen. RHA2a interacted with one of the plant-specific NAC [NAM('no apical meristem'), ATAF1/2, CUC2 ('cup-shaped cotyledons 2')] transcription factors, here named ANAC (abscisic acid-responsive NAC). The core RING-H2 domain was sufficient for the interaction. The ability of 11 structurally diverse RING-H2 domains to interact with ANAC was then examined. Robust interaction was detected for three of the domains, suggesting multi-specificity for the interaction. The domains that interacted with ANAC contain a glutamic acid residue in a position corresponding to a proline in many RING-H2 domains. Conversion of this glutamic acid residue into proline in RHA2a decreased its ability to interact with ANAC, most likely by changing the interaction surface. This suggested that a short, divergent region in RING-H2 domains modulate interaction specificity. ANAC contains a degenerate bipartite nuclear localization signal (NLS), while RHG1a, also identified as an ANAC interaction partner, contains a basic NLS. Both signals localized beta-glucuronidase reporter fusions to the nucleus. N-terminally truncated RHA2a also directed nuclear localization, apparently dependent on basic amino acids in the RING-H2 domain. Nuclear co-localization of the RING-H2 proteins and ANAC may enable their interaction in vivo to regulate the activity of the ANAC transcription factor.