Polyphosphoinositides play an important role in membrane trafficking and cell signalling. In plants, two PtdInsP isomers have been described, PtdIns3P and PtdIns4P. Here we report the identification of a third, PtdIns5P. Evidence is based on the conversion of the endogenous PtdInsP pool into PtdIns(4,5)P2 by a specific PtdIns5P 4-OH kinase, and on in vivo32P-labelling studies coupled to HPLC head-group analysis. In Chlamydomonas, 3–8% of the PtdInsP pool was PtdIns5P, 10–15% was PtdIns3P and the rest was PtdIns4P. In seedlings of Vicia faba and suspension-cultured tomato cells, the level of PtdIns5P was about 18%, indicating that PtdIns5P is a general plant lipid that represents a significant proportion of the PtdInsP pool. Activating phospholipase C (PLC) signalling in Chlamydomonas cells with mastoparan increased the turnover of PtdIns(4,5)P2 at the cost of PtdIns4P, but did not affect the level of PtdIns5P. This indicates that PtdIns(4,5)P2 is synthesized from PtdIns4P rather than from PtdIns5P during PLC signalling. However, when cells were subjected to hyperosmotic stress, PtdIns5P levels rapidly increased, suggesting a role in osmotic-stress signalling. The potential pathways of PtdIns5P formation are discussed.
Skip Nav Destination
Article navigation
December 2001
- PDF Icon PDF LinkFront Matter
Research Article|
November 26 2001
Identification of a new polyphosphoinositide in plants, phosphatidylinositol 5-monophosphate (PtdIns5P), and its accumulation upon osmotic stress
Harold J. G. MEIJER;
Harold J. G. MEIJER
1
∗Swammerdam Institute for Life Sciences, Department of Plant Physiology, University of Amsterdam, Kruislaan 318, NL-1098 SM, Amsterdam, The Netherlands
1To whom correspondence should be addressed (e-mail hmeijer@science.uva.nl).
Search for other works by this author on:
Christopher P. BERRIE;
Christopher P. BERRIE
†Department of Cell Biology and Oncology, Instituto di Ricerche Farmacologiche ‘'Mario Negri'’, Consorzio Mario Negri Sud, 66030 Santa Maria Imbaro (Chieti), Italy
Search for other works by this author on:
Cristiano IURISCI;
Cristiano IURISCI
†Department of Cell Biology and Oncology, Instituto di Ricerche Farmacologiche ‘'Mario Negri'’, Consorzio Mario Negri Sud, 66030 Santa Maria Imbaro (Chieti), Italy
Search for other works by this author on:
Nullin DIVECHA;
Nullin DIVECHA
‡Division of Cellular Biochemistry, The Netherlands Cancer Institute, Plesmanlaan 121, NL-1066 CX, Amsterdam, The Netherlands
Search for other works by this author on:
Alan MUSGRAVE;
Alan MUSGRAVE
∗Swammerdam Institute for Life Sciences, Department of Plant Physiology, University of Amsterdam, Kruislaan 318, NL-1098 SM, Amsterdam, The Netherlands
Search for other works by this author on:
Teun MUNNIK
Teun MUNNIK
∗Swammerdam Institute for Life Sciences, Department of Plant Physiology, University of Amsterdam, Kruislaan 318, NL-1098 SM, Amsterdam, The Netherlands
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
June 04 2001
Revision Received:
August 10 2001
Accepted:
September 28 2001
Online ISSN: 1470-8728
Print ISSN: 0264-6021
The Biochemical Society, London ©2001
2001
Biochem J (2001) 360 (2): 491–498.
Article history
Received:
June 04 2001
Revision Received:
August 10 2001
Accepted:
September 28 2001
Citation
Harold J. G. MEIJER, Christopher P. BERRIE, Cristiano IURISCI, Nullin DIVECHA, Alan MUSGRAVE, Teun MUNNIK; Identification of a new polyphosphoinositide in plants, phosphatidylinositol 5-monophosphate (PtdIns5P), and its accumulation upon osmotic stress. Biochem J 1 December 2001; 360 (2): 491–498. doi: https://doi.org/10.1042/bj3600491
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.