非豆科植物共生受体样蛋白激酶研究进展

植物根部能够与微生物形成相互依存、互惠互利的共生关系,非豆科植物根系主要与内生真菌形成菌根的共生体。共生受体样蛋白激酶(symbiosis receptor-like kinase,SYMRK)是植物识别菌根真菌诱导而产生的特异分子,它的蛋白结构由三个部分组成,即包含3个富含亮氨酸重复序列(LRRs)的胞外受体结合域、跨膜区和胞内蛋白激酶域。Symrk是控制共生形成的一个关键组分,该基因所编码的蛋白在植物识别和应答菌根真菌早期信号转导途径中是必需的。对Symrk基因的研究为进一步弄清植物-真菌共生的功能和作用机理打下了坚实的基础。     

植物凝集素类受体蛋白激酶研究进展

自然界中植物的生长发育受到各种环境变化的影响。为了响应外界各种环境条件,植物演化出一系列识别和传递环境信号的蛋白分子,其中比较典型的是植物细胞质膜上的类受体蛋白激酶(RLKs)。凝集素类受体蛋白激酶(LecRLKs)是类受体蛋白激酶家族中的一个亚族,它主要包含3个结构域:细胞外凝集素结构域、跨膜结构域和细胞内激酶结构域。根据细胞外凝集素结构域的不同,LecRLKs可分为3种不同类型:L、G和C型。近年来,研究表明LecRLKs在植物生物/非生物胁迫和发育调控中发挥非常重要的作用。该文综述了植物凝集素类受体蛋白激酶的研究历史、结构特点、分类以及生物学功能,并重点阐述凝集素类受体蛋白激酶在植物生物/非生物胁迫响应和调控发育方面的功能。对不同类型和不同功能的植物凝集素类受体蛋白激酶进行阐述将有利于对该类蛋白开展功能研究,并为作物改良提供有益借鉴。     

植物类受体蛋白激酶的研究进展

植物类受体蛋白激酶(receptor-like protein kinase,RLKs)通过胞外结构域识别病原信号分子,发生磷酸化、去磷酸化反应而开启或关闭下游靶蛋白,调节植物固有免疫反应,诱导抗病防御反应.目前对植物类受体蛋白激酶的功能、信号传导和配体识别等方面的研究已成为该领域的重点.本文对近年来国内外有关植物类受体蛋白激酶的结构、功能及其在植物抗病防御反应中的作用研究进行综述,为今后进一步深入研究植物类受体蛋白激酶的生理生化功能及应用提供参考.     

植物富含亮氨酸重复序列型类受体蛋白激酶的生物学功能

介绍了植物富含亮氨酸重复序列(leucine-rich repeat,LRR)型类受体蛋白激酶概念、最近发现的这类蛋白激酶的亚结构域特征;总结了目前已确定其功能的LRR型类受体蛋白激酶,并分别阐述了它们在参与植物抗逆性反应、发育调控及激素的信号转导等过程中的生物学功能;着重介绍和讨论了LRR型类受体蛋白激酶复合物之间及其与下游成分KAPP之间互作而产生信号传递的分子机理.最后展望了LRR型类受体蛋白激酶生物学功能、信号转导机制、以及应用于生产实践的研究前景.     

植物受体蛋白激酶的研究进展

在植物中存在一种由胞外结构域、跨膜区域和胞内的蛋白激酶区域三部分组成的跨膜受体蛋白激酶（receptor-lik protein kinases,RLKs)。该蛋白一方面作为胞外特异配基的受体,同时本身又是一种蛋白激酶。研究表明,植物细胞中的RLKs可能参与了植物细胞抗逆反应,植物形态发生、自交不亲和等生理生化反应,作者将从RLKs的结构、种类,基因表达方式及其植物生长和发育过程中的作用做简要介绍。     

共生通讯中的一个受体

两项独立的研究 (Ｓｔｒａｃｋｅｅｔａｌ;Ｅｎｄｒｅｅｔａｌ)从莲和豌豆植物以及豆科模型植物Ｍｅｄ ｉｃａｇｏｓａｔｉｖａ(紫花苜蓿的一个亲缘种 )中分离出了ＳＹＭＲＫ(共生受体样激酶 )基因。该类基因编码的蛋白对植物与细菌或真菌的共生体系的形成至关重要。此蛋白属于含有胞外富亮氨酸重复序列 (ｌｅｕｃｉｎｅ ｒｉｃｈｒｅｐｅａｔ,ＬＲＲ)的一类特殊受体蛋白族。植物中 ,ＬＲＲ受体蛋白所在的亚族一般都含有胞内丝氨酸 /苏氨酸 (Ｓｅｒ/Ｔｈｒ)激酶域 ,可以启动胞内的级联放大系统。动物中 ,这类蛋白组成Ｔｏｌｌ样受体群 ,在先…     

大豆类受体蛋白激酶基因GmRLCK的克隆及初步分析

植物类受体蛋白激酶(receptor-likeproteinkinase,RLK)在高等植物生长发育和环境刺激的信号传导中起着重要的作用。本文报告了一个新的大豆类受体蛋白激酶基因的全长cDNA克隆及对其基因结构和功能的初步分析。研究表明该基因序列编码的蛋白包含一个跨膜域、一个具有丝氨酸/苏氨酸激酶活性的胞内域和一个缺少N-末端信号肽的胞外域。采用生物信息学方法分析表明,该基因与一些拟南芥菜类受体蛋白激酶基因具有很高的相似性,这些激酶N-末端都缺少信号序列,属于植物胞质类受体激酶(receptor-likecytoplasmickinase,RLCK)亚家族。因此命名该大豆基因为GmRLCK(GenBankAccessionNo.AY687390)。对GmRLCK激酶域中磷酸化可能性较高的位点进行了预测。RT-PCR的结果表明,GmRLCK在大豆子叶、根、花以及豆荚中都有较高的表达,而在胚根、茎和成熟叶片中的表达相对较弱。进化分析表明GmRLCK与一些衰老相关的植物类受体蛋白激酶具有较近的亲缘关系。     

胰岛素样生长因子家族与肺癌

胰岛素样生长因子(IGFs)家族与多种肿瘤的发生发展关系密切。本文综述了IGFs和胰岛素样生长因子受体(IGFRs)以及胰岛素样生长因子结合蛋白(IGFBPs)在肺癌发生发展、增殖、侵袭、转移和凋亡中所起的作用及其作用机制。为肺癌的预防、治疗、预后提供新的思路。     

Toll 样受体与天然免疫

Toll样受体家族是一类模式识别受体,它介导了一个植物,昆虫,哺乳动物共同拥有的高度保守的信号通路。最近几年相继发现了多种人类Toll样受体以及相关的病原微生物配体,这些配体涵盖了病毒,细菌,真菌等微生物上多种保守的病原相关分子模式。可见Toll样受体在多种病原微生物及其产物的识别和免疫防御反应中有重要的作用。     

植物体细胞胚胎发生受体类蛋白激酶的生物学功能

体细胞胚胎发生受体类蛋白激酶(Somatic embryogenesis receptor-like kinases, SERKs)属于膜富亮氨酸重复序列受体类蛋白激酶(Leucine-rich repeat sequence receptor-like kinase, LRR-RLK)家族的第二亚类。SERK具有典型的胞外信号受体结构域、跨膜结构域和胞内激酶活性结构域, 研究发现SERKs在植物生命活动中承担着多个角色。文章简述了SERKs的典型结构域特征, 重点介绍该类蛋白在体细胞胚发生、生殖发育、激素感应和病理反应方面发挥的功能, 同时对该蛋白激酶的研究价值和应用前景进行了探讨。     

Multi-tasking of somatic embryogenesis receptor-like protein kinases

Receptor-like protein kinases (RLKs) are transmembrane proteins crucial for cell-to-cell and cell-to-environment communications. The extracellular domain of a RLK is responsible for perception of a specific extracellular ligand to trigger a unique intercellular signaling cascade, often via phosphorylation of cellular proteins. The signal is then transduced to the nucleus of a cell where it alters gene expression. There are more than 610 RLKs in Arabidopsis thaliana, only a handful of them have been functionally characterized. This review focuses on recent advances in our understanding of a small group of RLKs named somatic embryogenesis receptor-like protein kinases (SERKs). SERKs act as coreceptors in multiple signaling pathways via their physical interactions with distinct ligand-binding RLKs.     

Plant receptor kinases

Recent plant genome analyses have revealed a large number of genes encoding receptor-like kinases (RLKs) in plants. Theyare transmembrane proteins structurally related to the animal tyrosine and serin/threonine families with differences in their extracellular domains. There are more than 20 classes of plant RLKs, distinguished according to their extracellular domains, which can potentially bind an array of molecules. Although the majority of these RLKs remains uncharacterized, several members of this family are known to function in a diverse biological processes including plant growth and development, self-incompatibility, hormone perception and plant-microbe interactions. Despite knowledge of RLKs functions is increasing rapidly, yet major challenges remain. These include identifying ligands that activate RLKs and characterizing downstream pathways.     

Structure and function of the receptor-like protein kinases of higher plants

Cell surface receptors located in the plasma membrane have a prominent role in the initiation of cellular signalling. Recent evidence strongly suggests that plant cells carry cell surface receptors with intrinsic protein kinase activity. The plant receptor-like protein kinases (RLKs) are structurally related to the polypeptide growth factor receptors of animals which consist of a large extracytoplasmic domain, a single membrane spanning segment and a cytoplasmic domain of the protein kinase gene family. Most of the animal growth factor receptor protein kinases are tyrosine kinases; however, the plant RLKs all appear to be serine/threonine protein kinases. Based on structural similarities in their extracellular domains the RLKs fall into three categories: the S-domain class, related to the self-incompatibility locus glycoproteins of Brassica; the leucine-rich repeat class, containing a tandemly repeated motif that has been found in numerous proteins from a variety of eukaryotes; and a third class that has epidermal growth factor-like repeats. Distinct members of these putative receptors have been found in both monocytyledonous plants such as maize and in members of the dicotyledonous Brassicaceae. The diversity among plant RLKs, reflected in their structural and functional properties, has opened up a broad new area of investigation into cellular signalling in plants with far-reaching implications for the mechanisms by which plant cells perceive and respond to extracellular signals.     

Signalling through kinase-defective domains: the prevalence of atypical receptor-like kinases in plants

The structure of plant receptor-like kinases (RLKs) is similar to that of animal receptor tyrosine kinases (RTKs), and consists of an extracellular domain, a transmembrane span, and a cytoplasmic domain containing the conserved kinase domain. The mechanism by which animal RTKs, and probably plant RLKs, signal includes the dimerization of the receptor, their intermolecular phosphorylation, and the phosphorylation of downstream signalling proteins. However, atypical RTKs with a kinase-dead domain that signal through phosphorylation-independent mechanisms have also been described in animals. In the last few years, some atypical RLKs have also been reported in plants. Here these examples and their possible signalling mechanisms are reviewed. Plant genomes contain a much larger number of genes coding for receptor kinases than other organisms. The prevalence of atypical RLKs in plants is analysed here. A sequence analysis of the Arabidopsis kinome revealed that 13% of the kinase genes do not retain some of the residues that are considered as invariant within kinase catalytic domains, and are thus putatively kinase-defective. This percentage rises to close to 20% when analysing RLKs, suggesting that phosphorylation-independent mechanisms mediated by atypical RLKs are particularly important for signal transduction in plants.     

LRR-containing receptors regulating plant development and defense

Despite the presence of more than 400 genes that encode receptor-like kinases (RLKs) in the Arabidopsis thaliana genome, very little is known about the range of biological processes that they control, or the mechanisms by which they function. This review focuses on the most recent findings from studies of several leucine-rich-repeat (LRR) class RLKs in A. thaliana, and their implications for our understanding of plant receptor function and signaling. We compare the biological functions of plant and animal LRR-containing receptors, and the potential commonalities in the signaling mechanisms employed.     

The RLK/Pelle family of kinases

The RLK/Pelle class of proteins kinases is composed of over 600 members in Arabidopsis. Many of the proteins in this family are receptor-like kinases (RLK), while others have lost their extracellular domains and are found as cytoplasmic kinases. Proteins in this family that are RLKs have a variety of extracellular domains that drive function in a large number of processes, from cell wall interactions to disease resistance to developmental control. This review will briefly cover the major subclasses of RLK/Pelle proteins and their roles. In addition, two specific groups on RLKs will be discussed in detail, relating recent findings in Arabidopsis and how well these conclusions have been able to be translated to agronomically important species. Finally, some details on kinase activity and signal transduction will be addressed, along with the mystery of RLK/Pelle members lacking kinase enzymatic activity.     

The multifunctional leucine-rich repeat receptor kinase BAK1 is implicated in Arabidopsis development and immunity

Plant receptor-like kinases (RLKs) are transmembrane proteins with putative N-terminal extracellular ligand-binding domains and C-terminal intracellular protein kinase domains. RLKs have been implicated in multiple physiological programs including plant development and immunity to microbial infection. Arabidopsis thaliana gene expression patterns support an important role of this class of proteins in biotic stress adaptation. Here, we provide a comprehensive survey of plant immunity-related RLK gene expression. We further document the role of the Arabidopsis Brassinosteroid Insensitive 1 (BRI1)-associated receptor kinase 1 (BAK1) in seemingly unrelated biological processes, such as plant development and immunity, and propose a role of this protein as an adaptor molecule that is required for proper functionality of numerous RLKs. This view is supported by the identification of an additional RLK, PEPR1, and its closest homolog, PEPR2 as BAK1-interacting RLKs.     

Diverse roles of SERK family genes in plant growth,development and defense response

Plant receptor-like protein kinases (RLKs) are transmembrane proteins with an extracellular domain and an intracellular kinase domain, which enable plant perceiving diverse extracellular stimuli to trigger the intracellular signal transduction. The somatic embryogenesis receptor kinases (SERKs) code the leucine-rich-repeat receptor-like kinase (LRR-RLK), and have been demonstrated to associate with multiple ligand-binding receptors to regulate plant growth, root development, male fertility, stomatal development and movement, and immune responses. Here, we focus on the progress made in recent years in understanding the versatile functions of Arabidopsis SERK proteins, and review SERK proteins as co-receptor to perceive different endogenous and environmental cues in different signaling pathway, and discuss how the kinase activity of SERKs is regulated by various modification.     

植物凝集素类受体激酶参与抗病的研究进展

凝集素类受体激酶(Lectin receptor-like kinases,LecRLKs)是类受体激酶(Receptor-like kinases,RLKs)的一个亚族。根据结构域的不同,凝集素类受体激酶可分为L、G和C等3种类型。在植物中,凝集素类受体激酶被报道参与生物/非生物胁迫响应和植物发育调控。近年来,越来越多的研究发现,凝集素类受体激酶参与由细菌、真菌以及食草性昆虫等所引起的植物抗病反应。本文概述了植物凝集素类受体激酶的分类及结构特点,并系统阐述了该类激酶在植物抗病方面的作用,旨在增进对植物凝集素类受体激酶参与抗病功能的了解,并为作物抗病育种提供理论依据。