Specific Domain Structures Control Abscisic Acid-, Salicylic Acid-, and Stress-Mediated SIZ1 Phenotypes
Specific Domain Structures Control Abscisic Acid-, Salicylic Acid-, and Stress-Mediated SIZ1 Phenotypes
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DOI：
10.1104/pp.109.143719
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发表时间：
2009-12-01
期刊：
影响因子：
7.4
通讯作者：
Yun, Dae-Jin
中科院分区：
文献类型：
--
作者：
Cheong, Mi Sun;Park, Hyeong Cheol;Yun, Dae-Jin
SIZ 1（酵母SAP和MIZ 1）编码哺乳动物皮亚斯（活化STAT的蛋白质抑制剂）和酵母SIZ SUMO（小的遍在蛋白相关修饰剂）E3连接酶在拟南芥（Arabidopsis thaliana）中的唯一直系同源物。SIZ 1中的四个保守基序包括SAP（支架附着因子A/B/腺泡/皮亚斯结构域）、PINIT（脯氨酸-异亮氨酸-天冬酰胺-异亮氨酸-苏氨酸）、SP-RING（SIZ/PIAS-RING）和SXS（丝氨酸-X-丝氨酸，其中X是任何氨基酸）基序。此外，SIZ 1还含有植物皮亚斯蛋白典型的PHD（植物同源结构域）。我们确定的表型siz 1 -2敲除突变体转化SIZ 1等位基因携带点突变的预测域。结构域SP-RING是SUMO结合活性和SIZ 1核定位所必需的。水杨酸（SA）的积累和SA依赖表型的siz 1 -2，如减少植物大小，提高先天免疫力，脱落酸抑制子叶绿化，以及SA独立的基础耐热性没有补充的SIZ 1的SP-RING等位基因的改变。SXS结构域还控制SA积累，并参与脱落酸存在下萌发的幼苗子叶的绿化和扩展。PHD锌指结构域和PINIT基序的突变影响体内SUMO化。SIZ 1的PHD和/或PINIT结构域突变体等位基因在siz 1 -2中的表达促进了下胚轴响应于糖和光的伸长。SIZ 1的各个领域对植物科普环境的能力做出了独特的贡献。
SIZ1 (for yeast SAP and MIZ1) encodes the sole ortholog of mammalian PIAS (for protein inhibitor of activated STAT) and yeast SIZ SUMO (for small ubiquitin-related modifier) E3 ligases in Arabidopsis (Arabidopsis thaliana). Four conserved motifs in SIZ1 include SAP (for scaffold attachment factor A/B/acinus/PIAS domain), PINIT (for proline-isoleucine-asparagine-isoleucine-threonine), SP-RING (for SIZ/PIAS-RING), and SXS (for serine-X-serine, where X is any amino acid) motifs. SIZ1 contains, in addition, a PHD (for plant homeodomain) typical of plant PIAS proteins. We determined phenotypes of siz1-2 knockout mutants transformed with SIZ1 alleles carrying point mutations in the predicted domains. Domain SP-RING is required for SUMO conjugation activity and nuclear localization of SIZ1. Salicylic acid (SA) accumulation and SA-dependent phenotypes of siz1-2, such as diminished plant size, heightened innate immunity, and abscisic acid inhibition of cotyledon greening, as well as SA-independent basal thermotolerance were not complemented by the altered SP-RING allele of SIZ1. The SXS domain also controlled SA accumulation and was involved in greening and expansion of cotyledons of seedlings germinated in the presence of abscisic acid. Mutations of the PHD zinc finger domain and the PINIT motif affected in vivo SUMOylation. Expression of the PHD and/or PINIT domain mutant alleles of SIZ1 in siz1-2 promoted hypocotyl elongation in response to sugar and light. The various domains of SIZ1 make unique contributions to the plant's ability to cope with its environment.