Singh Supreet, Virdi Amardeep Singh, Jaswal Rajdeep, Chawla Mrinalini, Kapoor Sanjay, Mohapatra Samar B, Manoj Narayanan, Pareek Ashwani, Kumar Sanjay, Singh Prabhjeet
Department of Biotechnology, Guru Nanak Dev University, Amritsar, 143005, Punjab, India.
Biotechnology Division, Institute of Himalayan Bioresource Technology, Palampur, 176061 Himachal Pradesh, India.
Biochimie. 2017 Jun;137:115-123. doi: 10.1016/j.biochi.2017.03.010. Epub 2017 Mar 18.
Imposition of different biotic and abiotic stress conditions results in an increase in intracellular levels of Ca which is sensed by various sensor proteins. Calmodulin (CaM) is one of the best studied transducers of Ca signals. CaM undergoes conformational changes upon binding to Ca and interacts with different types of proteins, thereby, regulating their activities. The present study reports the cloning and characterization of a sorghum cDNA encoding a protein (SbGRBP) that shows homology to glycine-rich RNA-binding proteins. The expression of SbGRBP in the sorghum seedlings is modulated by heat stress. The SbGRBP protein is localized in the nucleus as well as in cytosol, and shows interaction with CaM that requires the presence of Ca. SbGRBP depicts binding to single- and also double-stranded DNA. Fluorescence spectroscopic analyses suggest that interaction of SbGRBP with nucleic acids may be modulated after binding with CaM. To our knowledge, this is the first study to provide evidence for interaction of a stress regulated glycine-rich RNA-binding protein with CaM.
施加不同的生物和非生物胁迫条件会导致细胞内钙离子水平升高，这会被各种传感蛋白感知。钙调蛋白（CaM）是研究得最为深入的钙信号转导蛋白之一。CaM在与钙结合后会发生构象变化，并与不同类型的蛋白质相互作用，从而调节它们的活性。本研究报道了一个高粱cDNA的克隆和特征分析，该cDNA编码一种与富含甘氨酸的RNA结合蛋白具有同源性的蛋白质（SbGRBP）。SbGRBP在高粱幼苗中的表达受热胁迫调节。SbGRBP蛋白定位于细胞核和细胞质中，并显示出与需要钙离子存在的CaM相互作用。SbGRBP显示出与单链和双链DNA的结合。荧光光谱分析表明，SbGRBP与核酸的相互作用在与CaM结合后可能会受到调节。据我们所知，这是第一项为应激调节的富含甘氨酸的RNA结合蛋白与CaM相互作用提供证据的研究。
