Mishra Neeti Sanan, Tuteja Renu, Tuteja Narendra
International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
Arch Biochem Biophys. 2006 Aug 1;452(1):55-68. doi: 10.1016/j.abb.2006.05.001. Epub 2006 May 24.
Protein phosphorylation is the most important mechanism for controlling many fundamental cellular processes in all living organisms including plants. A specific class of serine/threonine protein kinases, the mitogen-activated protein kinases (MAP kinases) play a central role in the transduction of various extra- and intracellular signals and are conserved throughout eukaryotes. These generally function via a cascade of networks, where MAP kinase (MAPK) is phosphorylated and activated by MAPK kinase (MAPKK), which itself is activated by MAPKK kinase (MAPKKK). Signaling through MAP kinase cascade can lead to cellular responses including cell division, differentiation as well as response to various stresses. In plants, MAP kinases are represented by multigene families and are organized into a complex network for efficient transmission of specific stimuli. Putative plant MAP kinase cascades have been postulated based on experimental analysis of in vitro interactions between specific MAP kinase components. These cascades have been tested in planta following expression of epitope-tagged kinases in protoplasts. It is known that signaling for cell division and stress responses in plants are mediated through MAP kinases and even auxin, ABA and possibly ethylene and cytokinin also utilize a MAP kinase pathway. Most of the biotic (pathogens and pathogen-derived elicitors) including wounding and abiotic stresses (salinity, cold, drought, and oxidative) can induce defense responses in plants through MAP kinase pathways. In this article we have covered the historical background, biochemical assay, activation/inactivation, and targets of MAP kinases with emphasis on plant MAP kinases and the responses regulated by them. The cross-talk between plant MAP kinases is also discussed to bring out the complexity within this three-component module.
蛋白质磷酸化是控制包括植物在内的所有生物体中许多基本细胞过程的最重要机制。一类特定的丝氨酸/苏氨酸蛋白激酶，即丝裂原活化蛋白激酶（MAP激酶），在各种细胞外和细胞内信号的转导中起着核心作用，并且在整个真核生物中都是保守的。这些通常通过一系列网络发挥作用，其中MAP激酶（MAPK）被MAP激酶激酶（MAPKK）磷酸化并激活，而MAPKK本身又被MAPKK激酶（MAPKKK）激活。通过MAP激酶级联的信号传导可导致细胞反应，包括细胞分裂、分化以及对各种胁迫的反应。在植物中，MAP激酶由多基因家族代表，并组织成一个复杂的网络，以有效地传递特定刺激。基于对特定MAP激酶组分之间体外相互作用的实验分析，推测了假定的植物MAP激酶级联。在原生质体中表达表位标记的激酶后，已在植物中对这些级联进行了测试。已知植物中细胞分裂和胁迫反应的信号传导是通过MAP激酶介导的，甚至生长素、脱落酸以及可能的乙烯和细胞分裂素也利用MAP激酶途径。大多数生物胁迫（病原体和病原体衍生的激发子），包括伤口和非生物胁迫（盐度、寒冷、干旱和氧化），都可以通过MAP激酶途径诱导植物的防御反应。在本文中，我们涵盖了MAP激酶的历史背景、生化测定、激活/失活以及靶点，重点是植物MAP激酶及其调控的反应。还讨论了植物MAP激酶之间的相互作用，以揭示这个三组分模块中的复杂性。
