Non-TZF Transcriptional Activator AtC3H12 Negatively Affects Seed Germination and Seedling Development in Arabidopsis.

Hye-Yeon Seok,Taehyoung Kim,Yong-Hwan Moon,Sun-Young Lee

doi:10.3390/ijms23031572

Hye-Yeon Seok, Taehyoung Kim + Show 2 more

Open Access

https://doi.org/10.3390/ijms23031572

Copy DOI

Abstract

CCCH zinc finger proteins are a large protein family and are classified as either tandem CCCH zinc finger (TZF) or non-TZF proteins. The roles of TZF genes in several plants have been well determined, whereas the functions of many non-TZF genes in plants remain uncharacterized. Herein, we describe biological and molecular functions of AtC3H12, an Arabidopsis non-TZF protein containing three CCCH zinc finger motifs. AtC3H12 has orthologs in several plant species but has no paralog in Arabidopsis. AtC3H12-overexpressing transgenic plants (OXs) germinated slower than wild-type (WT) plants, whereas atc3h12 mutants germinated faster than WT plants. The fresh weight (FW) and primary root lengths of AtC3H12 OX seedlings were lighter and shorter than those of WT seedlings, respectively. In contrast, FW and primary root lengths of atc3h12 seedlings were heavier and longer than those of WT seedlings, respectively. AtC3H12 was localized in the nucleus and displayed transactivation activity in both yeast and Arabidopsis. We found that the 97–197 aa region of AtC3H12 is an important part for its transactivation activity. Detection of expression levels and analysis of Arabidopsis transgenic plants harboring a PAtC3H12::GUS construct showed that AtC3H12 expression increases as the Arabidopsis seedlings develop. Taken together, our results demonstrate that AtC3H12 negatively affects seed germination and seedling development as a nuclear transcriptional activator in Arabidopsis. To our knowledge, this is the first report to show that non-TZF proteins negatively affect plant development as nuclear transcriptional activators.

Highlights

Zinc finger proteins constitute a large group of protein families categorized to different types, such as C2H2, C2C2, C2HC, C2C2C2C2, C2HCC2C2, and CCCH, on the basis of the number and order of cysteine (Cys) and histidine (His) residues that bind to a zinc ion [1,2]
Sixty-eight CCCH zinc finger protein genes have been recognized in the Arabidopsis (Arabidopsis thaliana) genome, whereas 67 genes have been recognized in rice (Oryza sativa) [5]
We demonstrated that AtC3H12 negatively affects seed germination and seedling development as a nuclear transcriptional activator

Summary

Introduction

Zinc finger proteins constitute a large group of protein families categorized to different types, such as C2H2, C2C2, C2HC, C2C2C2C2, C2HCC2C2, and CCCH, on the basis of the number and order of cysteine (Cys) and histidine (His) residues that bind to a zinc ion [1,2] They participate in various biological processes, including transcription, apoptosis, and protein assembly [1,3,4]. In addition to its role in RNA metabolism, most recent studies demonstrated that CCCH zinc finger proteins modulate transcription. Two Arabidopsis TZF proteins, AtC3H14 and AtC3H15/AtCDM1, display transactivation activity and bind to both DNA and RNA in vitro [4]. We selected a previously uncharacterized Arabidopsis non-TZF protein, AtC3H12 showing strong transactivation activity and characterized its biological and molecular functions. Our findings will enable us to expand our knowledge of the functions of non-TZF proteins as transcriptional regulators

AtC3H12 Has Three CCCH Zinc Finger Motifs

RNA Isolation and RT-PCR

4.10. Phenotype Analysis