The N-terminal und motif of the arabidopsis U-box E3 ligase pub18 is critical for the negative regulation of aba-mediated stomatal movement and determines its ubiquitination specificity for exocyst subunit Exo70B1

Dong Hye Seo, Min Yong Ahn, Ki Youl Park, Eun Yu Kim, Woo Taek Kim

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

The Arabidopsis thaliana U-box E3 ligases PUB18/PUB19 and PUB22/PUB23 are negative regulators of drought stress responses. PUB18/PUB19 regulate the drought stress response in an abscisic acid (ABA)-dependent manner, whereas PUB22/PUB23 regulate this response in an ABA-independent manner. A major structural difference between PUB18/PUB19and PUB22/PUB23 is the presence of the UND (U-box N-terminal domain). Here, we focused on elucidating the molecular mechanism that mediates the functional difference between PUB18 and PUB22 and found that the was critically involved in the negative regulation of ABA-mediated stomatal movements. Exo70B1, a subunit of the exocyst complex, wasidentified as a target of PUB18, whereas Exo70B2 was a substrate of PUB22. However, the ΔUND-PUB18 derivative failed toubiquitinate Exo70B1, but ubiquitinated Exo70B2. By contrast, the UNDPUB18-PUB22 chimeric protein ubiquitinated Exo70B1 instead of Exo70B2, suggesting that the ubiquitination specificities of PUB18 and PUB22 to Exo70B1 and Exo70B2,respectively, are dependent on the presence or absence of the UNDPUB18 motif. The ABA-insensitive phenotypes of the pub18 pub19 exo70b1 triple mutant were reminiscent of those of exo70b1 rather than pub18 pub19, indicating that Exo70B1 functions downstream of PUB18. Overall, our results suggest that the UNDPUB18 motif is crucial for the negative regulation ofABA-dependent stomatal movement and for determination of its ubiquitination specificity to Exo70B1.

Original languageEnglish
Pages (from-to)2952-2973
Number of pages22
JournalPlant Cell
Volume28
Issue number12
DOIs
Publication statusPublished - 2016 Dec 1

Fingerprint

stomatal movement
Abscisic Acid
Ubiquitin-Protein Ligases
Ubiquitination
ligases
Arabidopsis
abscisic acid
Droughts
stress response
water stress
Ubiquitinated Proteins
recombinant fusion proteins
Arabidopsis thaliana
Phenotype
phenotype
mutants
ubiquitination

All Science Journal Classification (ASJC) codes

  • Plant Science
  • Cell Biology

Cite this

@article{af61f110548d47cbbf8542aaba3affef,
title = "The N-terminal und motif of the arabidopsis U-box E3 ligase pub18 is critical for the negative regulation of aba-mediated stomatal movement and determines its ubiquitination specificity for exocyst subunit Exo70B1",
abstract = "The Arabidopsis thaliana U-box E3 ligases PUB18/PUB19 and PUB22/PUB23 are negative regulators of drought stress responses. PUB18/PUB19 regulate the drought stress response in an abscisic acid (ABA)-dependent manner, whereas PUB22/PUB23 regulate this response in an ABA-independent manner. A major structural difference between PUB18/PUB19and PUB22/PUB23 is the presence of the UND (U-box N-terminal domain). Here, we focused on elucidating the molecular mechanism that mediates the functional difference between PUB18 and PUB22 and found that the was critically involved in the negative regulation of ABA-mediated stomatal movements. Exo70B1, a subunit of the exocyst complex, wasidentified as a target of PUB18, whereas Exo70B2 was a substrate of PUB22. However, the ΔUND-PUB18 derivative failed toubiquitinate Exo70B1, but ubiquitinated Exo70B2. By contrast, the UNDPUB18-PUB22 chimeric protein ubiquitinated Exo70B1 instead of Exo70B2, suggesting that the ubiquitination specificities of PUB18 and PUB22 to Exo70B1 and Exo70B2,respectively, are dependent on the presence or absence of the UNDPUB18 motif. The ABA-insensitive phenotypes of the pub18 pub19 exo70b1 triple mutant were reminiscent of those of exo70b1 rather than pub18 pub19, indicating that Exo70B1 functions downstream of PUB18. Overall, our results suggest that the UNDPUB18 motif is crucial for the negative regulation ofABA-dependent stomatal movement and for determination of its ubiquitination specificity to Exo70B1.",
author = "Seo, {Dong Hye} and Ahn, {Min Yong} and Park, {Ki Youl} and Kim, {Eun Yu} and Kim, {Woo Taek}",
year = "2016",
month = "12",
day = "1",
doi = "10.1105/tpc.16.00347",
language = "English",
volume = "28",
pages = "2952--2973",
journal = "Plant Cell",
issn = "1040-4651",
publisher = "American Society of Plant Biologists",
number = "12",

}

The N-terminal und motif of the arabidopsis U-box E3 ligase pub18 is critical for the negative regulation of aba-mediated stomatal movement and determines its ubiquitination specificity for exocyst subunit Exo70B1. / Seo, Dong Hye; Ahn, Min Yong; Park, Ki Youl; Kim, Eun Yu; Kim, Woo Taek.

In: Plant Cell, Vol. 28, No. 12, 01.12.2016, p. 2952-2973.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The N-terminal und motif of the arabidopsis U-box E3 ligase pub18 is critical for the negative regulation of aba-mediated stomatal movement and determines its ubiquitination specificity for exocyst subunit Exo70B1

AU - Seo, Dong Hye

AU - Ahn, Min Yong

AU - Park, Ki Youl

AU - Kim, Eun Yu

AU - Kim, Woo Taek

PY - 2016/12/1

Y1 - 2016/12/1

N2 - The Arabidopsis thaliana U-box E3 ligases PUB18/PUB19 and PUB22/PUB23 are negative regulators of drought stress responses. PUB18/PUB19 regulate the drought stress response in an abscisic acid (ABA)-dependent manner, whereas PUB22/PUB23 regulate this response in an ABA-independent manner. A major structural difference between PUB18/PUB19and PUB22/PUB23 is the presence of the UND (U-box N-terminal domain). Here, we focused on elucidating the molecular mechanism that mediates the functional difference between PUB18 and PUB22 and found that the was critically involved in the negative regulation of ABA-mediated stomatal movements. Exo70B1, a subunit of the exocyst complex, wasidentified as a target of PUB18, whereas Exo70B2 was a substrate of PUB22. However, the ΔUND-PUB18 derivative failed toubiquitinate Exo70B1, but ubiquitinated Exo70B2. By contrast, the UNDPUB18-PUB22 chimeric protein ubiquitinated Exo70B1 instead of Exo70B2, suggesting that the ubiquitination specificities of PUB18 and PUB22 to Exo70B1 and Exo70B2,respectively, are dependent on the presence or absence of the UNDPUB18 motif. The ABA-insensitive phenotypes of the pub18 pub19 exo70b1 triple mutant were reminiscent of those of exo70b1 rather than pub18 pub19, indicating that Exo70B1 functions downstream of PUB18. Overall, our results suggest that the UNDPUB18 motif is crucial for the negative regulation ofABA-dependent stomatal movement and for determination of its ubiquitination specificity to Exo70B1.

AB - The Arabidopsis thaliana U-box E3 ligases PUB18/PUB19 and PUB22/PUB23 are negative regulators of drought stress responses. PUB18/PUB19 regulate the drought stress response in an abscisic acid (ABA)-dependent manner, whereas PUB22/PUB23 regulate this response in an ABA-independent manner. A major structural difference between PUB18/PUB19and PUB22/PUB23 is the presence of the UND (U-box N-terminal domain). Here, we focused on elucidating the molecular mechanism that mediates the functional difference between PUB18 and PUB22 and found that the was critically involved in the negative regulation of ABA-mediated stomatal movements. Exo70B1, a subunit of the exocyst complex, wasidentified as a target of PUB18, whereas Exo70B2 was a substrate of PUB22. However, the ΔUND-PUB18 derivative failed toubiquitinate Exo70B1, but ubiquitinated Exo70B2. By contrast, the UNDPUB18-PUB22 chimeric protein ubiquitinated Exo70B1 instead of Exo70B2, suggesting that the ubiquitination specificities of PUB18 and PUB22 to Exo70B1 and Exo70B2,respectively, are dependent on the presence or absence of the UNDPUB18 motif. The ABA-insensitive phenotypes of the pub18 pub19 exo70b1 triple mutant were reminiscent of those of exo70b1 rather than pub18 pub19, indicating that Exo70B1 functions downstream of PUB18. Overall, our results suggest that the UNDPUB18 motif is crucial for the negative regulation ofABA-dependent stomatal movement and for determination of its ubiquitination specificity to Exo70B1.

UR - http://www.scopus.com/inward/record.url?scp=85009813062&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85009813062&partnerID=8YFLogxK

U2 - 10.1105/tpc.16.00347

DO - 10.1105/tpc.16.00347

M3 - Article

VL - 28

SP - 2952

EP - 2973

JO - Plant Cell

JF - Plant Cell

SN - 1040-4651

IS - 12

ER -