Aquaporin AqpZ is involved in cell volume regulation and sensitivity to osmotic stress in Synechocystis sp. strain PCC 6803

Masaro Akai, Kiyoshi Onai, Megumi Morishita, Hiroyuki Mino, Toshiaki Shijuku, Hisataka Maruyama, Fumihito Arai, Shigeru Itoh, Akihiro Hazama, Vanessa Checchetto, Ildikò Szabò, Yoshinori Yukutake, Makoto Suematsu, Masato Yasui, Masahiro Ishiura, Nobuyuki Uozumia

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

The moderately halotolerant cyanobacterium Synechocystis sp. strain PCC 6803 contains a plasma membrane aquaporin, AqpZ. We previously reported that AqpZ plays a role in glucose metabolism under photomixotrophic growth conditions, suggesting involvement of AqpZ in cytosolic osmolarity homeostasis. To further elucidate the physiological role of AqpZ, we have studied its gene expression profile and its function in Synechocystis. The expression level of aqpZ was regulated by the circadian clock. AqpZ activity was insensitive to mercury in Xenopus oocytes and in Synechocystis, indicating that the AqpZ can be categorized as a mercury-insensitive aquaporin. Stopped-flow light-scattering spectrophotometry showed that addition of sorbitol and NaCl led to a slower decrease in cell volume of the Synechocystis ΔaqpZ strain than the wild type. The ΔaqpZ cells were more tolerant to hyperosmotic shock by sorbitol than the wild type. Consistent with this, recovery of oxygen evolution after a hyperosmotic shock by sorbitol was faster in the ΔaqpZ strain than in the wild type. In contrast, NaCl stress had only a small effect on oxygen evolution. The amount of AqpZ protein remained unchanged by the addition of sorbitol but decreased after addition of NaCl. This decrease is likely to be a mechanism to alleviate the effects of high salinity on the cells. Our results indicate that Synechocystis AqpZ functions as a water transport system that responds to daily oscillations of intracellular osmolarity.

Original languageEnglish
Pages (from-to)6828-6836
Number of pages9
JournalJournal of Bacteriology
Volume194
Issue number24
DOIs
Publication statusPublished - 2012 Oct

Fingerprint

Synechocystis
Aquaporins
Osmotic Pressure
Cell Size
Sorbitol
Mercury
Osmolar Concentration
Shock
Oxygen
Circadian Clocks
Spectrophotometry
Salinity
Cyanobacteria
Xenopus
Transcriptome
Oocytes
Homeostasis
Cell Membrane
Light
Glucose

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology

Cite this

Aquaporin AqpZ is involved in cell volume regulation and sensitivity to osmotic stress in Synechocystis sp. strain PCC 6803. / Akai, Masaro; Onai, Kiyoshi; Morishita, Megumi; Mino, Hiroyuki; Shijuku, Toshiaki; Maruyama, Hisataka; Arai, Fumihito; Itoh, Shigeru; Hazama, Akihiro; Checchetto, Vanessa; Szabò, Ildikò; Yukutake, Yoshinori; Suematsu, Makoto; Yasui, Masato; Ishiura, Masahiro; Uozumia, Nobuyuki.

In: Journal of Bacteriology, Vol. 194, No. 24, 10.2012, p. 6828-6836.

Research output: Contribution to journalArticle

Akai, M, Onai, K, Morishita, M, Mino, H, Shijuku, T, Maruyama, H, Arai, F, Itoh, S, Hazama, A, Checchetto, V, Szabò, I, Yukutake, Y, Suematsu, M, Yasui, M, Ishiura, M & Uozumia, N 2012, 'Aquaporin AqpZ is involved in cell volume regulation and sensitivity to osmotic stress in Synechocystis sp. strain PCC 6803', Journal of Bacteriology, vol. 194, no. 24, pp. 6828-6836. https://doi.org/10.1128/JB.01665-12
Akai, Masaro ; Onai, Kiyoshi ; Morishita, Megumi ; Mino, Hiroyuki ; Shijuku, Toshiaki ; Maruyama, Hisataka ; Arai, Fumihito ; Itoh, Shigeru ; Hazama, Akihiro ; Checchetto, Vanessa ; Szabò, Ildikò ; Yukutake, Yoshinori ; Suematsu, Makoto ; Yasui, Masato ; Ishiura, Masahiro ; Uozumia, Nobuyuki. / Aquaporin AqpZ is involved in cell volume regulation and sensitivity to osmotic stress in Synechocystis sp. strain PCC 6803. In: Journal of Bacteriology. 2012 ; Vol. 194, No. 24. pp. 6828-6836.
@article{1cb39d3e6c5545f780e7c0bd41414420,
title = "Aquaporin AqpZ is involved in cell volume regulation and sensitivity to osmotic stress in Synechocystis sp. strain PCC 6803",
abstract = "The moderately halotolerant cyanobacterium Synechocystis sp. strain PCC 6803 contains a plasma membrane aquaporin, AqpZ. We previously reported that AqpZ plays a role in glucose metabolism under photomixotrophic growth conditions, suggesting involvement of AqpZ in cytosolic osmolarity homeostasis. To further elucidate the physiological role of AqpZ, we have studied its gene expression profile and its function in Synechocystis. The expression level of aqpZ was regulated by the circadian clock. AqpZ activity was insensitive to mercury in Xenopus oocytes and in Synechocystis, indicating that the AqpZ can be categorized as a mercury-insensitive aquaporin. Stopped-flow light-scattering spectrophotometry showed that addition of sorbitol and NaCl led to a slower decrease in cell volume of the Synechocystis ΔaqpZ strain than the wild type. The ΔaqpZ cells were more tolerant to hyperosmotic shock by sorbitol than the wild type. Consistent with this, recovery of oxygen evolution after a hyperosmotic shock by sorbitol was faster in the ΔaqpZ strain than in the wild type. In contrast, NaCl stress had only a small effect on oxygen evolution. The amount of AqpZ protein remained unchanged by the addition of sorbitol but decreased after addition of NaCl. This decrease is likely to be a mechanism to alleviate the effects of high salinity on the cells. Our results indicate that Synechocystis AqpZ functions as a water transport system that responds to daily oscillations of intracellular osmolarity.",
author = "Masaro Akai and Kiyoshi Onai and Megumi Morishita and Hiroyuki Mino and Toshiaki Shijuku and Hisataka Maruyama and Fumihito Arai and Shigeru Itoh and Akihiro Hazama and Vanessa Checchetto and Ildik{\`o} Szab{\`o} and Yoshinori Yukutake and Makoto Suematsu and Masato Yasui and Masahiro Ishiura and Nobuyuki Uozumia",
year = "2012",
month = "10",
doi = "10.1128/JB.01665-12",
language = "English",
volume = "194",
pages = "6828--6836",
journal = "Journal of Bacteriology",
issn = "0021-9193",
publisher = "American Society for Microbiology",
number = "24",

}

TY - JOUR

T1 - Aquaporin AqpZ is involved in cell volume regulation and sensitivity to osmotic stress in Synechocystis sp. strain PCC 6803

AU - Akai, Masaro

AU - Onai, Kiyoshi

AU - Morishita, Megumi

AU - Mino, Hiroyuki

AU - Shijuku, Toshiaki

AU - Maruyama, Hisataka

AU - Arai, Fumihito

AU - Itoh, Shigeru

AU - Hazama, Akihiro

AU - Checchetto, Vanessa

AU - Szabò, Ildikò

AU - Yukutake, Yoshinori

AU - Suematsu, Makoto

AU - Yasui, Masato

AU - Ishiura, Masahiro

AU - Uozumia, Nobuyuki

PY - 2012/10

Y1 - 2012/10

N2 - The moderately halotolerant cyanobacterium Synechocystis sp. strain PCC 6803 contains a plasma membrane aquaporin, AqpZ. We previously reported that AqpZ plays a role in glucose metabolism under photomixotrophic growth conditions, suggesting involvement of AqpZ in cytosolic osmolarity homeostasis. To further elucidate the physiological role of AqpZ, we have studied its gene expression profile and its function in Synechocystis. The expression level of aqpZ was regulated by the circadian clock. AqpZ activity was insensitive to mercury in Xenopus oocytes and in Synechocystis, indicating that the AqpZ can be categorized as a mercury-insensitive aquaporin. Stopped-flow light-scattering spectrophotometry showed that addition of sorbitol and NaCl led to a slower decrease in cell volume of the Synechocystis ΔaqpZ strain than the wild type. The ΔaqpZ cells were more tolerant to hyperosmotic shock by sorbitol than the wild type. Consistent with this, recovery of oxygen evolution after a hyperosmotic shock by sorbitol was faster in the ΔaqpZ strain than in the wild type. In contrast, NaCl stress had only a small effect on oxygen evolution. The amount of AqpZ protein remained unchanged by the addition of sorbitol but decreased after addition of NaCl. This decrease is likely to be a mechanism to alleviate the effects of high salinity on the cells. Our results indicate that Synechocystis AqpZ functions as a water transport system that responds to daily oscillations of intracellular osmolarity.

AB - The moderately halotolerant cyanobacterium Synechocystis sp. strain PCC 6803 contains a plasma membrane aquaporin, AqpZ. We previously reported that AqpZ plays a role in glucose metabolism under photomixotrophic growth conditions, suggesting involvement of AqpZ in cytosolic osmolarity homeostasis. To further elucidate the physiological role of AqpZ, we have studied its gene expression profile and its function in Synechocystis. The expression level of aqpZ was regulated by the circadian clock. AqpZ activity was insensitive to mercury in Xenopus oocytes and in Synechocystis, indicating that the AqpZ can be categorized as a mercury-insensitive aquaporin. Stopped-flow light-scattering spectrophotometry showed that addition of sorbitol and NaCl led to a slower decrease in cell volume of the Synechocystis ΔaqpZ strain than the wild type. The ΔaqpZ cells were more tolerant to hyperosmotic shock by sorbitol than the wild type. Consistent with this, recovery of oxygen evolution after a hyperosmotic shock by sorbitol was faster in the ΔaqpZ strain than in the wild type. In contrast, NaCl stress had only a small effect on oxygen evolution. The amount of AqpZ protein remained unchanged by the addition of sorbitol but decreased after addition of NaCl. This decrease is likely to be a mechanism to alleviate the effects of high salinity on the cells. Our results indicate that Synechocystis AqpZ functions as a water transport system that responds to daily oscillations of intracellular osmolarity.

UR - http://www.scopus.com/inward/record.url?scp=84870687262&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84870687262&partnerID=8YFLogxK

U2 - 10.1128/JB.01665-12

DO - 10.1128/JB.01665-12

M3 - Article

C2 - 23043001

AN - SCOPUS:84870687262

VL - 194

SP - 6828

EP - 6836

JO - Journal of Bacteriology

JF - Journal of Bacteriology

SN - 0021-9193

IS - 24

ER -