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1.
PP2C(PP2C-type protein phosphatases)蛋白磷酸酶是一类丝氨酸/苏氨酸残基蛋白磷酸酶,植物体内目前已经发现了4种PP2C蛋白磷酸酶:ABI,AtP2C-HABl,AtPP2CA以及MP2C.大量的研究表明植物PP2C蛋白磷酸酶参与了ABA信号转导途径的负调控功能.就高等植物PP2C的分类及其对ABA信号转导途径的负调控功能的研究进展进行了综述.  相似文献   

2.
蛋白磷酸酶是蛋白质可逆磷酸化过程中2个关键酶之一,蛋白磷酸酶2C(protein phosphatase 2C, PP2C)是蛋白磷酸酶的重要成员。PP2C是一类丝氨酸/苏氨酸蛋白磷酸酶,可以调控真核生物细胞生命活动。PP2C成员主要参与激素信号转导途径,尤其可作为脱落酸信号途径的关键调节因子,能响应各种生物和非生物胁迫,在器官发育和种子萌发等方面也具有重要的促进作用。在不同的植物中也发现了越来越多的PP2C成员,该酶在不同的植物、不同的生长环境以及不同的生理活动中均有不同的调控方式,这也是目前及今后对PP2C成员的研究方向。本文主要介绍了植物PP2C家族的结构特点、亚细胞定位及其在生长发育、激素信号转导、逆境胁迫方面的研究现状,以及在提高植物生物产量、促进果实发育等方面的新进展。  相似文献   

3.
PP2C蛋白磷酸酶(protein phosphatase 2C,PP2C)是一类丝氨酸/苏氨酸残基蛋白磷酸酶,是ABA信号转导的核心组分,其广泛参与ABA的各种信号转导途径。本文综述了主要PP2C的功能,包括ABI1和ABI2、HAB1、AHG3/At PP2CA以及其他发现的成员。现已发现野生型ABI1和ABI2磷酸酶是ABA信号转导的负调控因子,ABI1的突变会阻断ABA激活钙通道,抑制ABA-依赖的SRK2E/OST1的激活。通过对苔藓中的Pp ABI1A和Pp ABI1B的研究,为进化守恒提供了遗传证明。HAB1的隐性突变体对ABA高度敏感,抑制种子萌发,离体HAB1可使OST1去磷酸化,HAB1经历可变剪切会产生发挥对立作用的两个剪切变体。抑制At PP2CA会加强植株抗低温胁迫能力,PP2CA可能与微管并列、独立地调控气孔运动等。同时,本文总结了关于PP2C调控的相关发现,包括PP2C与PYL的相互作用以及PP2C与其他因子的相互作用及其对PP2C的影响,例如磷脂酸(PA)会抑制ABI1功能,过表达At MYB44会减弱PP2C编码基因表达,ABI2需要CPL介导ABA信号转导等。  相似文献   

4.
2C类蛋白磷酸酶(PP2C-type protein phosphatases,PP2C)是一类丝氨酸/ 苏氨酸残基蛋白磷酸酶,在细胞内以单体形式存在,酶催化活性依赖于Mg2+或Mn2+.PP2C通过去磷酸化作用负调控蛋白激酶级联信号系统,参与细胞周期、胁迫信号转导、基因转录、蛋白质翻译及翻译后修饰等细胞活动过程.H2O2、不饱和脂肪酸、Ca2+/CaM、脂质信号分子等均可调节PP2C的活性.  相似文献   

5.
2C类蛋白磷酸酶(PP2C-type protein phosphatases,PP2C)是一类丝氨酸/ 苏氨酸残基蛋白磷酸酶,在细胞内以单体形式存在,酶催化活性依赖于Mg2 或Mn2 .PP2C通过去磷酸化作用负调控蛋白激酶级联信号系统,参与细胞周期、胁迫信号转导、基因转录、蛋白质翻译及翻译后修饰等细胞活动过程.H2O2、不饱和脂肪酸、Ca2 /CaM、脂质信号分子等均可调节PP2C的活性.  相似文献   

6.
植物激素脱落酸(ABA)参与调控植物生长发育各个阶段,并在植物对多种胁迫的抗逆反应中起着重要作用。PPR基因家族是拟南芥最大的基因家族之一,PPR蛋白在调控植物生长发育与响应逆境胁迫过程中发挥重要作用,然而参与ABA信号转导的线粒体PPR蛋白仍有待进一步研究。本研究发现拟南芥线粒体PPR蛋白APPR6的2个T-DNA插入突变体在萌发与萌发后幼苗早期生长过程中对外源ABA超敏,报道APPR6参与ABA信号转导为进一步阐明线粒体PPR蛋白的作用机制以及复杂的ABA信号网络提供了新的信息。  相似文献   

7.
欧美杨是中纬度地区最适合的短轮伐期工业用材集约经营树种之一,然而盐渍、干旱和低温严重影响了欧美杨的生长发育和产量。本文利用RT-PCR等技术克隆出欧美杨PP2C基因并进行了序列分析。PdPP2C基因开放阅读框为1 320 bp,编码439个氨基酸。蛋白质序列分析表明,PP2C蛋白N端保守性不强,C端有保守的蛋白磷酸酶区域。荧光定量PCR分析表明,该基因在欧美杨根、成熟叶、顶端叶和茎中都有表达且根中表达量最高。逆境胁迫分析表明,该基因受NaCl、ABA和干旱等诱导表达。干旱和盐胁迫处理下转PdPP2C基因拟南芥与野生型相比生长受到较少抑制,且叶绿素含量上升,丙二醛含量下降,表明PdPP2C基因作为一种蛋白磷酸酶提高了拟南芥的抗逆性。   相似文献   

8.
2C型丝氨酸/苏氨酸蛋白磷酸酶(PP2C)是植物体内脱落酸ABA信号传导关键负调控酶,在植物耐非生物胁迫中发挥着重要的作用。本研究利用RT-PCR技术,克隆出编码杜梨PP2C蛋白的基因Pb PP2C,其核苷酸序列全长1 353 bp,开放阅读框长1 263 bp,编码422个氨基酸残基,这些残基中包括了与二价金属离子结合的MED、DGH、DG和D结构域。系统发生分析结果表明,该氨基酸与拟南芥AHG3亲缘关系最近。实时荧光定量PCR分析结果表明:盐胁迫条件下,Pb PP2C基因在根、茎、叶中的表达12 h达到峰值,同时在根中72 h达到第二个峰值;干旱胁迫条件下,Pb PP2C基因在根、茎、叶中表达72 h达到峰值。说明Pb PP2C与杜梨耐盐和耐干旱胁迫存在紧密关联。  相似文献   

9.
环境胁迫下植物细胞ABA的信号转导途径   总被引:1,自引:0,他引:1  
植物激素脱落酸(ABA)调控很多重要的生长过程并诱导植物对各种逆境条件如干旱,高盐,低温等的耐受性,和ABA信号转导途径一起成为现在的研究热点。笔者主要介绍环境胁迫下ABA合成与代谢,细胞ABA的信号转导途径中受体,第二信使和蛋白磷酸和去磷酸化的研究进展,以及对由该信号系统产生的生理及基因方面作用的内容予以综述,以对ABA信号途径的分子机制有更深入了解。  相似文献   

10.
2C型蛋白磷酸酶(protein phosphatase 2C,PP2C)基因是ABA信号途径中主要组成部分,为分析其在木薯非生物胁迫和块根采后生理性变质(post-harvest physiological deterioration,PPD)中的作用,采用RT-PCR技术从木薯叶片(SC124)中克隆得到MePP2...  相似文献   

11.
Abscisic acid (ABA) is an essential hormone for plants to survive environmental stresses. At the center of the ABA signaling network is a subfamily of type 2C protein phosphatases (PP2Cs), which form exclusive interactions with ABA receptors and subfamily 2 Snfl-related kinase (SnRK2s). Here, we report a SnRK2-PP2C complex structure, which reveals marked similarity in PP2C recognition by SnRK2 and ABA receptors. In the complex, the kinase activation loop docks into the active site of PP2C, while the conserved ABA-sensing tryptophan of PP2C inserts into the kinase catalytic cleft, thus mimicking receptor-PP2C interactions. These structural results provide a simple mechanism that directly couples ABA binding to SnRK2 kinase activation and highlight a new paradigm of kinase-phosphatase regulation through mutual packing of their catalytic sites.  相似文献   

12.
植物蛋白磷酸酶2C(PP2C)能够通过影响植物体内多种生物学过程在环境胁迫响应中发挥重要作用.为研究栽培大豆PP2C家族成员在盐胁迫中的功能,通过生物信息学手段结合转录组学分析对栽培大豆PP2C家族进行了系统探究.在栽培大豆中共鉴定出126个PP2C家族成员,并将其在进化树上分为11个亚家族,同一亚家族的成员具有类似的...  相似文献   

13.
Oxysterol-binding protein (OSBP) is the founding member of a family of sterol-binding proteins implicated in vesicle transport, lipid metabolism, and signal transduction. Here, OSBP was found to function as a cholesterol-binding scaffolding protein coordinating the activity of two phosphatases to control the extracellular signal-regulated kinase (ERK) signaling pathway. Cytosolic OSBP formed a approximately 440-kilodalton oligomer with a member of the PTPPBS family of tyrosine phosphatases, the serine/threonine phosphatase PP2A, and cholesterol. This oligomer had dual specific phosphatase activity for phosphorylated ERK (pERK). When cell cholesterol was lowered, the oligomer disassembled and the level of pERK rose. The oligomer also disassembled when exposed to oxysterols. Increasing the amount of OSBP oligomer rendered cells resistant to the effects of cholesterol depletion and decreased the basal level of pERK. Thus, cholesterol functions through its interaction with OSBP outside of membranes to regulate the assembly of an oligomeric phosphatase that controls a key signaling pathway in the cell.  相似文献   

14.
Entry into mitosis in eukaryotes requires the activity of cyclin-dependent kinase 1 (Cdk1). Cdk1 is opposed by protein phosphatases in two ways: They inhibit activation of Cdk1 by dephosphorylating the protein kinases Wee1 and Myt1 and the protein phosphatase Cdc25 (key regulators of Cdk1), and they also antagonize Cdk1's own phosphorylation of downstream targets. A particular form of protein phosphatase 2A (PP2A) containing a B55δ subunit (PP2A- B55δ) is the major protein phosphatase that acts on model CDK substrates in Xenopus egg extracts and has antimitotic activity. The activity of PP2A-B55δ is high in interphase and low in mitosis, exactly opposite that of Cdk1. We report that inhibition of PP2A-B55δ results from a small protein, known as α-endosulfine (Ensa), that is phosphorylated in mitosis by the protein kinase Greatwall (Gwl). This converts Ensa into a potent and specific inhibitor of PP2A-B55δ. This pathway represents a previously unknown element in the control of mitosis.  相似文献   

15.
Terrestrial plants lose water primarily through stomata, pores on the leaves. The hormone abscisic acid (ABA) decreases water loss by regulating opening and closing of stomata. Here, we show that phospholipase Dalpha1 (PLDalpha1) mediates the ABA effects on stomata through interaction with a protein phosphatase 2C (PP2C) and a heterotrimeric GTP-binding protein (G protein) in Arabidopsis. PLDalpha1-produced phosphatidic acid (PA) binds to the ABI1 PP2C to signal ABA-promoted stomatal closure, whereas PLDalpha1 and PA interact with the Galpha subunit of heterotrimeric G protein to mediate ABA inhibition of stomatal opening. The results reveal a bifurcating signaling pathway that regulates plant water loss.  相似文献   

16.
The plant protein phosphatase 2Cs(PP2Cs) play an essential role in response to stress and abscisic acid(ABA) signaling pathway. However, to date, no systemic characterization of the PP2Cs has yet been conducted in potato(Solanum tuberosum L.). In the study, a comprehensive research was performed on genome-wide identification and expression analysis of StPP2C genes in potato. A total of 78 potato StPP2C genes were identified based on specific structure of PP2C domain, which were distributed across 11 out of 12 potato chromosomes and divided into 12(A–L) phylogenetic branches. The result from gene duplication analysis showed that 14 StPP2Cs were involved in gene tandem duplication and 8 genes formed fragment duplication events, which indicated that both tandem and fragment duplication contributed to the expansion of the gene family in evolution. Exon–intron structural analysis showed that they had a wide range of exon numbers. Analysis of protein conservative motif demonstrated that StPP2Cs contained more similar motif structures in the same phylogenetic branches. The cis-elements in StPP2C gene promoter regions were mainly responded to light, phytohormone and abiotic stress. Most of them exhibited tissue-specific expression patterns, and some members could differentially express under abiotic stress. The evidence suggested that StPP2C genes may contribute to different functions in several physiological stress and environmental stress conditions. This study could provide new insights to further investigate StPP2C functional characteristics responding to various stresses in potato.  相似文献   

17.
18.
Calmodulin (CaM) is a major effector for the intracellular actions of Ca2+ in nearly all cell types. We identified a CaM-binding protein, designated regulator of calmodulin signaling (RCS). G protein-coupled receptor (GPCR)-dependent activation of protein kinase A (PKA) led to phosphorylation of RCS at Ser55 and increased its binding to CaM. Phospho-RCS acted as a competitive inhibitor of CaM-dependent enzymes, including protein phosphatase 2B (PP2B, also called calcineurin). Increasing RCS phosphorylation blocked GPCR- and PP2B-mediated suppression of L-type Ca2+ currents in striatal neurons. Conversely, genetic deletion of RCS significantly increased this modulation. Through a molecular mechanism that amplifies GPCR- and PKA-mediated signaling and attenuates GPCR- and PP2B-mediated signaling, RCS synergistically increases the phosphorylation of key proteins whose phosphorylation is regulated by PKA and PP2B.  相似文献   

19.
Protein phosphatases: properties and role in cellular regulation   总被引:47,自引:0,他引:47  
Protein phosphorylation is a principal regulatory mechanism in the control of almost all cellular processes. The nature of the protein phosphatases that participate in these reactions has been a subject of controversy. Four enzymes, termed protein phosphatases 1, 2A, 2B, and 2C, account for virtually all of the phosphatase activity toward phosphoproteins involved in controlling glycogen metabolism, glycolysis, gluconeogenesis, fatty acid synthesis, cholesterol synthesis, and protein synthesis. The properties, physiological roles, and mechanisms for regulating the four protein phosphatases are reviewed.  相似文献   

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