Temperature-dependent hyper-activation of monoglucosyldiacylglycerol synthase is post-translationally regulated in Synechocystis sp. PCC 6803

Shimojima, Mie; Tsuchiya, Mami; Ohta, Hiroyuki

doi:10.1016/j.febslet.2009.06.033

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Volume 583, Issue 14 , Pages 2372-2376, 21 July 2009

Temperature-dependent hyper-activation of monoglucosyldiacylglycerol synthase is post-translationally regulated in Synechocystis sp. PCC 6803

Edited by Peter Brzezinski

Mie Shimojima
- Research Center for the Evolving Earth and Planets, Tokyo Institute of Technology, 4259-B65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
- Center for Biological Resources and Informatics, Tokyo Institute of Technology, 4259-B65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
- Corresponding author. Address: Center for Biological Resources and Informatics, Tokyo Institute of Technology, 4259-B65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan. Fax: +81 45 924 5823.
- These authors contributed equally.
Mami Tsuchiya
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259-B65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
- These authors contributed equally.
Hiroyuki Ohta
- Research Center for the Evolving Earth and Planets, Tokyo Institute of Technology, 4259-B65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
- Center for Biological Resources and Informatics, Tokyo Institute of Technology, 4259-B65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan

Received 27 May 2009; received in revised form 17 June 2009; accepted 17 June 2009. published online 22 June 2009.

Abstract

The mechanism of monoglucosyldiacylglycerol (MGlcDG) increase following heat shock in Synechocystis sp. PCC 6803 was examined by measuring MGlcDG synthase (Sll1377) activity. Temperature-dependent activation of Sll1377 was observed in the membrane fraction of Synechocystis sp. PCC 6803, whereas the Sll1377 protein level remained unchanged, suggesting that the activity is post-translationally regulated without covalent modification of Sll1377 by soluble enzymes. Four individual mutations introduced into recombinant Sll1377 (D147, D200, R329, and R331) significantly reduced the activity and blocked temperature-dependent activation, suggesting that these amino acid residues are essential for Sll1377 activity at both normal growth temperature and the higher temperature.

Abbreviations: MGlcDG, monoglucosyldiacylglycerol, MGDG, monogalactosyldiacylglycerol, DAG, diacylglycerol

Keywords: Cyanobacterium, Monoglucosyldiacylglycerol, Glycosyltransferase, Heat shock