Pyrophosphate modulates plant stress responses via SUMOylation
Authors: Frauke Melchior
M Görkem Patir-Nebioglu
Rüdiger Hell
Zaida Andrés
Fabian Fink
Karin Schumacher
Masayoshi Maeshima
Melanie Krebs
Katarzyna Drzewicka
Sebastian Schuck
Michael Büttner
Nicolas Stankovic-Valentin
Shoji Segami
Journal: eLife (2019)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: A. thaliana; E1-activating enzyme; S. cerevisiae; SUMO; biochemistry
Affiliations: Department Cell Biology, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany., Center for Molecular Biology of Heidelberg University (ZMBH) and DKFZ - ZMBH Alliance, Heidelberg, Germany., Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan., Metabolomics Core Technology Platform, Centre for Organismal Studies (COS), Heidelberg University, Heidelberg, Germany.

Abstract:  Pyrophosphate (PPi), a byproduct of macromolecule biosynthesis is maintained at low levels by soluble inorganic pyrophosphatases (sPPase) found in all eukaryotes. In plants, H+-pumping pyrophosphatases (H+-PPase) convert the substantial energy present in PPi into an electrochemical gradient. We show here, that both cold- and heat stress sensitivity of fugu5 mutants lacking the major H+-PPase isoform AVP1 is correlated with reduced SUMOylation. In addition, we show that increased PPi concentrations interfere with SUMOylation in yeast and we provide evidence that SUMO activating E1-enzymes are inhibited by micromolar concentrations of PPi in a non-competitive manner. Taken together, our results do not only provide a mechanistic explanation for the beneficial effects of AVP1 overexpression in plants but they also highlight PPi as an important integrator of metabolism and stress tolerance. 

Retracted: No

PubPeer comments:
 ![file] , 
 Concern about Figure 3E: Unexpected similarities between lanes that represent different experimental conditions (22u00b0C or 4u00b0C) and different genetic backgrounds (fugu5-1 or UBQ:PPa5-GFP fugu5-1) , 
 Dear Aneurus, thx for sharing your concerns. Iu2019m currently on vacation but we hope to be able to provide the original images in the next days. Regards, Karin Schumacher , 
 Dear authors, the upper image in your comment #5 is just a vertical compression of the right-half of published Figure 3E. , 
 Dear Aneurus, we hope that these images address your concerns . Karin Schumacher and Gorkem Patir-Nebioglu , 
 ![file] ![file] , 
 I am not sure that there is a manipulation problem in Fig. 3. My concern is that lane 3 of the 22u00b0 sample (fugu5-1) is more or less identical to lane 4 of the 4u00b0 sample (UBQ-PPa5-GFP fugu5-1). I don t understand this. It looks to me as if there has been incorrect sample loading on either the 22u00b0 or the 4u00b0 westerns. , 
 Copy pasted from https: elifesciences.org articles 44213#annotations:VqvKuj5tEem7tzs5bJGJXQ  There are relevant discussions on PubPeer about data presented in this paper: https: pubpeer.com publications 597F4A6EC25F0EE8787C936C4E7DCD We are corresponding with the authors and editors as a result. Andy Collings, Executive Editor, eLife , 
 Concern also about Figure 5B: the lower half of lane at 28u00b0C responds differently when Input Levels of contrast are squeezed. Reason is background is much brighter there. Other blots do not bahave that way (see bottom of my panel). Of note, here same anti-SUMO as Fig 3E was used. Could authors please provide original blot of Figure 5B? ![file] , 
 Dear Aneurus, I finally had the chance to discuss the matter with my colleagues. The blots in Figure 3E have indeed been manipulated in an inappropriate manner and we are very grateful that you brought this to our attention. However, the manipulation does not affect the outcome of the experiment. Our conclusion that SUMOylation is reduced in *fugu5* is based on the quantification of independent replicate experiments. In the meantime, we are running another repetition of the experiment to be able to provide a suitable blot for the figure. Beyond that, everybody involved has learned a very painful lesson and we all hope to proof in the future that this was an exceptional break of the rules of good scientific practice and does not at all reflect how we do science! Karin Schumacher , 
 ![file] , 
 Update: We have initiated retraction of eLife 2019;8:e44213 based on irregularities associated with the Western Blots shown in Figures 3D and E as well as Figures 4C and D performed by Gorkem Patir-Nebioglu (GPN). Initiated by reports on PubPeer, we have further investigated the matter and have found that in both Figures 3 and 4 blots were spliced together from different original images without indication and a single lane was copied twice in Figure 3E. In addition, GPN has admitted to have intentionally loaded less protein for *fugu5* at 4u00b0C (Figure 3) and 40u00b0C (Figure 4). Both issues represent severe violations of the rules of good scientific practice and retraction of the manuscript is thus mandatory. We are currently running independent repetitions of the experiments in question and hope to be able to clarify the situation in the near future. In the meantime, our sincere apologies go to all of our collaborators and readers of our manuscript. Karin Schumacher , 
 Retraction notice: Published 20, February 2019  The authors are retracting the eLife paper cited above based on irregularities associated with the western blots shown in Figures 3D and E as well as Figures 4C and D performed by Gorkem Patir-Nebioglu (GPN). Initiated by reports on PubPeer, the authors have investigated the matter and have found that in both Figures 3 and 4 the blots were spliced together from different original images without indication and a single lane was copied twice in Figure 3E. In addition, GPN has admitted to having intentionally loaded less protein for fugu5 at 4u00b0C (Figure 3) and 40u00b0C (Figure 4). The authors are currently running independent repetitions of the experiments in question and hope to be able to provide appropriate data in the near future. However, with the currently available data, the conclusion that SUMOylation is reduced in fugu5 mutants is not justified and all authors have agreed to retract the paper. Thanks to the authors for promptly responding and addressing the concerns. ,