Plant PIP2-dependent phospholipase D activity is regulated by phosphorylation
Authors: Jan Martinec
Olga Valentová
Zuzana Novotná
Radovan Hynek
Martin Potocký
Jan Linek
Journal: FEBS Letters (2003)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Phospholipase D; PLD; phosphatidylinositol-4,5-bisphosphate; PIP2; Brassica oleracea

Abstract:  Phospholipase D (PLD) forms the major family of phospholipases that was first discovered and cloned in plants. In this report we have shown, for the first time, that C2 phosphatidylinositol-4,5-bisphosphate (PIP2)-dependent PLD(s) from 5 day hypocotyls of Brassica oleracea associated with plasma membrane is covalently modified-phosphorylated. Pre-incubation of the plasma membrane fraction with acid phosphatase resulted in concentration-dependent inhibition of PIP2-dependent PLD activity. Using matrix-assisted laser desorption/ionization time of flight mass spectrometry of tryptic in-gel digests, the BoPLDgamma(1,2) isoform was identified. Comparing the spectra of the proteins obtained from the plasma membrane fractions treated and non-treated with acid phosphatase, three peptides differing in the mass of the phosphate group (80 Da) were revealed: TMQMMYQTIYK, EVADGTVSVYNSPR and KASKSRGLGK which possess five potential Ser/Thr phosphorylation sites. Our findings suggest that a phosphorylation/dephosphorylation mechanism may be involved in the regulation of plant PIP2-dependent PLDgamma activity. 

Retracted: No

PubPeer comments:
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 2021 correction. https: www.nature.com articles s41388-021-01653-4 Correction to: Oncogene (2013) 32:1050u20131058 https: doi.org 10.1038 onc.2012.107 Following publication of this article, the authors became aware of errors in several figures. When preparing the combined Fig. 1a, two tubulin bands were inadvertently duplicated. Initially, the Calu3 and A549 cell lines were not loaded on the same blots than other cell lines. Original tubulin immunoblots were retrieved. A corrected version of Fig. 1a is provided in which the correct tubulin data are presented and indicated by a splice line to highlight non-continuous blots. figure1 Fig. 1 In Figs. 1d and 2c, the same actin immunoblots were inadvertently used to illustrate loading controls of sip14ARF experiments. The original actin immunoblot of Fig. 1d was found and replaced in the corrected figure. The original actin control blot of Fig. 2c could not be retrieved but data from additional experiments are shown that confirm the published results regarding the negative impact of p14ARF knock-down on STAT3 phosphorylation. Likewise, questions raised on tubulin immunoblots in Figs. 3a and 4a are addressed by showing additional experiments that confirm (1) the induction of apoptosis following PTP-RT neutralization that correlates with P-STAT3 activation in H3255 cells (Fig. 3a, other original data) and (2) the upregulation of bcl-2 expression following STAT3 neutralization in H3255 cells (Fig. 4a, other original data). In Fig. 5d, the authors point the fact that both EGF treatments (30u2009min and 24u2009h) were part of the same experiment and loaded on the same immunoblots (except for p-EGFR) with the same control data point (NT). In the published paper, the data were presented into two distinct panels to illustrate effect of EGF on EGFR activation (EGF 30u2009min) and on p14ARF expression (EGF 24u2009h). Splice lines have been added in the corrected Fig. 5d to highlight non-continuous blots. All corrected figures and additional data are included below. The results and scientific conclusions of this paper have not been affected by these modifications. The authors apologize to readers for any inconvenience caused. ,