Plastid casein kinase 2 (CK2), which is a major Ser/Thr-specific enzyme in higher organisms, plays an essential role in plant development and diverse abiotic stresses. CKB1 is a regulatory subunit beta of CK2. To expand our understand of functions of the CKB1 gene in Arabidopsis thaliana, protein changes among wild-type (WT) and CKB1 gain- and loss-of-function mutants were compared. Proteins extracted from the CKB1 knockout mutant and overexpressing mutant were compared with Col-0 plants using 2D-PAGE. Proteins regulated by CKB1 were identified with matrix-assisted laser desorption ionisation time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF), and its transcript was verified by qRT-PCR. Bioinformatics analysis, including gene ontology and protein-protein interaction analysis, were employed. The results of mass spectra and bioinformatics analysis suggest that CKB1 may have functions in regulation of the ribosomal protein L10 (RPL10) family and is involved in ultraviolet-B (UV-B) response. Furthermore, qRT-PCR verification showed CKB1 expression was up-regulated by UV-B stress. The expression levels of five genes in the RPL10 family were reduced in the ckb1 T-DNA insertion mutants, whereas they increased in the CKB1 overexpressing mutants under both normal conditions and UV-B treatment. In conclusion, CKB1 has important functions in UV-B radiation stress. Our study implies that CKB1 positively regulates UV-B radiation stress signalling, possibly through modulating expression of the RPL10 family.

中文翻译：

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CKB1调节核糖体蛋白L10家族基因的表达，并在UV-B反应中起作用。

塑性酪蛋白激酶2（CK2）是高等生物中主要的Ser / Thr特异性酶，在植物发育和各种非生物胁迫中起着至关重要的作用。CKB1是CK2的调节性亚基beta。为了扩大我们对拟南芥中CKB1基因功能的了解，比较了野生型（WT）和CKB1功能获得和丧失功能的突变体之间的蛋白质变化。使用2D-PAGE将从CKB1基因敲除突变体和过表达突变体中提取的蛋白质与Col-0植物进行比较。用基质辅助激光解吸电离飞行时间/飞行时间质谱（MALDI-TOF / TOF）鉴定由CKB1调控的蛋白质，并通过qRT-PCR验证其转录本。采用了生物信息学分析，包括基因本体论和蛋白质-蛋白质相互作用分析。质谱和生物信息学分析的结果表明，CKB1可能具有调节核糖体蛋白L10（RPL10）家族的功能，并参与了紫外线B（UV-B）反应。此外，qRT-PCR验证显示CKB1表达受UV-B胁迫上调。在正常条件下和UV-B处理下，ckb1 T-DNA插入突变体中RPL10家族中五个基因的表达水平降低，而在CKB1过表达的突变体中它们升高。总之，CKB1在UV-B辐射应力中具有重要功能。我们的研究表明，CKB1可能通过调节RPL10家族的表达来积极调节UV-B辐射应力信号。