Subcellular Distribution of NTL Transcription Factors in Arabidopsis thaliana. (7th September 2015)

• Record Type: Journal Article
• Authors: Liang, Mingwei; Li, Hongjuan; Zhou, Fang; Li, Huiyong; Liu, Jin; Hao, Yi; Wang, Yingdian; Zhao, Heping; Han, Shengcheng
• Is Part Of: Traffic. Volume 16:Number 10(2015:Oct.)
• Page Start: 1062
• Page End: 1074
• Publication Date: 2015-09-07
• Subjects: Arabidopsis -- NTL transcription factor -- subcellular localization -- tail‐anchored protein; Biological transport -- Periodicals; 571.6
• DOI: 10.1111/tra.12311
• Languages: English
• ISSNs: 1398-9219

Abstract

Abstract : NAC with a transmembrane (TM) motif1‐like (NTL) transcription factors, containing three regions: the N‐terminal NAC domain (ND), the middle regulation region (RR), and the C‐terminal TM domain, belong to the tail‐anchored proteins. Although these NTLs play numerous essential roles in plants, their subcellular distribution and the mechanism of translocation into the nucleus (NU) remain unclear. In this study, we found that most of the full‐length NTLs were localized in the endoplasmic reticulum (ER), with the exception of NTL11 and NTL5, which were restricted to the NU. Furthermore, we found that NTL11 contains a TM domain, whereas NTL5 does not. The ND of all of the NTLs was responsible for nuclear localization in plants. After truncation of the TM domain, NTL8_NR, NTL10_NR and NTL13_NR localized in the cytoplasm (CT) and NU, and other NTL_NRs were only localized in the NU, suggesting that the RR of NTL8, NTL10 and NTL13 contains some inhibitory region to mask the nuclear localization signal sequence in the ND domain and permit their diffusion between CT and NU. Furthermore, the N‐terminus of NTL11 was translocated to the NU, but the C‐terminus was degraded in Arabidopsis mesophyll protoplasts. The chimeric construct of NTL11_ND with NTL10_RR and TM domain (11ND‐10RT) was localized exclusively in the ER, and not in the NU. However, 10ND‐11RT was found mainly in the NU. Our results indicated that the TM domain is essential for NTL targeting the ER and the N‐terminal fragment, including ND and RR, is translocated into the NU after activation through proteolytic cleavage events upon stimulation by internal and external environmental signals. Abstract : NAC with a transmembrane (TM) motif1‐like proteins (NTLs) are a class of NAC transcription factors containing a TM domain at their C‐terminus. Using a transient transformation approach in Arabidopsis mesophyll protoplasts, we showed that 12 NTLs, with the exception of NTL11 and NTL5, are anchored to the ER membrane. Furthermore, the N‐terminal NAC domain and the regulation region of NTLs were proved to be responsible for NTLs entering the nucleus. These results indicated that proteolytic activation of NTLs is a regulatory scheme active in plants during various stress situations.