Department of Molecular Biology and Genetic Engineering, College of Basic Sciences & Humanities, G. B. Pant University of Ag.& Tech., Pantnagar 263145, Uttarakhand, India.
Rani Laxmi Bai Central Agriculture University, Jhansi, Uttar Pradesh 284003, India.
Gene. 2019 Sep 25;714:144004. doi: 10.1016/j.gene.2019.144004. Epub 2019 Jul 24.
Calreticulin (CRT) is calcium binding protein of endoplasmic reticulum (ER) which performs plethora of functions besides it's role as molecular chaperone. Among the three different isoforms of this protein, CRT3 is most closely related to primitive CRT gene of higher plants. Based on their distinct structural and functional organisation, the plant CRTs have been known to contain three different domains: N, P and the C domain. The domain organisation and various biochemical characterstics of plant and animal CRTs are common with the exception of some differences. In plant calreticulin, the important N-glycosylation site(s) are replaced by the glycan chain(s) and several consensus sequences for in vitro phosphorylation by protein kinase CK2 (casein kinase-2), are also present unlike the animal calreticulin. Biotic and abiotic stresses play a significant role in bringing down the crop production. The role of various phytohormones in defense against fungal pathogens is well documented. CRT3 has been reported to play important role in protecting the plants against fungal and bacterial pathogens and in maintaining plant innate immunity. There is remarkable crosstalk between CRT mediated signalling and biotic, abiotic stress, and phytohormone mediated signalling pathways The role of CRT mediated pathway in mitigating biotic and abiotic stress can be further explored in plants so as to strategically modify it for development of stress tolerant plants.
钙网蛋白（CRT）是内质网（ER）的钙结合蛋白，除了作为分子伴侣外，它还具有多种功能。在该蛋白的三种不同同工型中，CRT3 与高等植物原始 CRT 基因最为密切相关。基于其独特的结构和功能组织，植物 CRT 已知包含三个不同的结构域：N、P 和 C 结构域。植物和动物 CRT 的结构域组织和各种生化特性是共同的，除了一些差异。在植物钙网蛋白中，重要的 N-糖基化位点（s）被聚糖链（s）取代，并且存在几个用于体外由蛋白激酶 CK2（酪蛋白激酶-2）磷酸化的保守序列，而不像动物钙网蛋白那样。生物和非生物胁迫在降低作物产量方面起着重要作用。各种植物激素在防御真菌病原体方面的作用已有详细记载。CRT3 已被报道在保护植物免受真菌和细菌病原体以及维持植物固有免疫方面发挥重要作用。CRT 介导的信号转导与生物、非生物胁迫和植物激素介导的信号转导途径之间存在显著的串扰。可以进一步研究 CRT 介导的途径在减轻生物和非生物胁迫中的作用，以便在植物中对其进行战略性修饰，以开发出对胁迫耐受的植物。
