Abstract
Tandem CCCH zinc finger (TZF) proteins are the essential components of processing bodies (PBs) and stress granules (SGs), which play critical roles in growth development and stress response in both animals and plants through posttranscriptional regulation of target mRNA. In this study, we characterized the biological and molecular functions of a novel tandem zinc finger protein, OsTZF7. The expression of OsTZF7 was upregulated by abiotic stresses, including polyethylene glycol (PEG) 4000, NaCl, and abscisic acid (ABA) in rice. Accordingly, the overexpression of OsTZF7 increased drought tolerance and enhanced sensitivity to exogenous ABA in rice, whereas the knockdown of OsTZF7 resulted in the opposite phenotype. RNA-seq analysis revealed that genes related to “response to stress,” “abscisic acid signaling,” “methylated histone binding,” and “cytoplasmic mRNA processing body” are regulated by OsTZF7. We demonstrated that OsTZF7 can traffic between the nucleus and PBs/SGs, and the leucine-rich nuclear export signal (NES) mediates the nuclear export of OsTZF7. Additionally, we revealed that OsTZF7 can bind adenine- and uridine-rich (AU-rich) element (ARE) or ARE-like motifs within the 3′ untranslated region of downregulated mRNAs, and interact with PWWP family proteins in vitro. Together, these results indicate that OsTZF7 positively regulates drought response in rice via ABA signaling and may be involved in mRNA turnover.
Highlights
The CCCH zinc finger proteins contain one or more CCCH-type zinc finger motifs
Consistent with the Quantitative Real-time PCR (qRT-PCR) result, strong GUS activity was detected in the young leaf, young root, mature root, stem, sheath, coleoptile, pistil, and anthers, whereas lower activity was detected in the mature leaf, lemmas, and paleae (Figure 1B)
PEG4000 and salt stresses upregulated the mRNA level of OsTZF7, and it reached the maximum level at 12 h in shoot and 3 h in root, respectively (Figure 1C)
Summary
The CCCH zinc finger proteins contain one or more CCCH-type zinc finger motifs (three cysteines followed by one histidine). TZFs can recruit the CCR4-NOT complex to target mRNAs and induce mRNA decay (Otsuka et al, 2019) Another feature of TZF proteins is that they shuttle between different cellular compartments, such as from the nucleus to the cytoplasm, and between different cytoplasmic RNA granules, like polysomes, stress granules (SGs), and processing bodies (Pbodies, PBs), where they are considered to play various roles in RNA metabolism (Bogamuwa and Jang, 2014; MaldonadoBonilla, 2014; Fu and Blackshear, 2017). Tristetraprolin (TTP, the prototype of mammalian TZF proteins) can bind the AREs at the 3 UTR of tumor necrosis factor-α (TNFα) and trigger TNF-α mRNA decay by recruiting deadenylation and decapping complexes. The destabilization of mRNA mediated by TTP has been reported in other cytokines, such as interleukin (IL)-16, IL-8, IL-22, IL-23, interferon (IFN)-γ, granulocyte-macrophage colony-stimulating factor (GM-CSF), and some chemokines (Brooks and Blackshear, 2013)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
