HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Turnover of LeACS2, a wound-inducible 1-aminocyclopropane-1-carboxylic acid synthase in tomato, is regulated by phosphorylation/dephosphorylation.

Abstract
1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) is the rate-limiting enzyme of the ethylene biosynthesis pathway. ACS is regulated both transcriptionally and post-translationally. We previously reported that LeACS2, a wound-inducible ACS in tomato (Solanum lycopersicum), is phosphorylated in vivo, and suggested that phosphorylation regulates protein stability rather than enzymatic activity. In this report, we demonstrate that phosphorylation/dephosphorylation of LeACS2 regulates its turnover upstream of the ubiquitin-26S-proteasome degradation pathway. Pulse-chase experiments coupled with treatment with protein kinase/phosphatase inhibitors demonstrated that LeACS2 is stabilized by phosphorylation and degraded after dephosphorylation. The amount of LeACS2 affected by the protein kinase/phosphatase inhibitors significantly influenced cellular ACS activity, ACC content, and ethylene production levels in tomato fruit tissue, suggesting that post-translational regulation by phosphorylation plays an important role in the control of ethylene production. A calcium-dependent protein kinase (CDPK), LeCDPK2, was isolated as one of the protein kinases that are able to phosphorylate LeACS2 at Ser-460. LeACS2 was immediately phosphorylated after translation by CDPK and mitogen-activated protein kinase at different sites in response to wound signaling and almost all functional LeACS2 molecules are phosphorylated in the cell. Phosphorylation at both sites was required for LeACS2 stability.
AuthorsYusuke Kamiyoshihara, Mineko Iwata, Tomoko Fukaya, Miho Tatsuki, Hitoshi Mori
JournalThe Plant journal : for cell and molecular biology (Plant J) Vol. 64 Issue 1 Pg. 140-50 (Oct 2010) ISSN: 1365-313X [Electronic] England
PMID20659278 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
Copyright© 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.
Chemical References
  • Plant Proteins
  • Lyases
  • 1-aminocyclopropanecarboxylate synthase
Topics
  • Gene Expression Regulation, Plant
  • Lyases (genetics, metabolism)
  • Solanum lycopersicum (enzymology, genetics)
  • Phosphorylation
  • Plant Proteins (genetics, metabolism)
  • Protein Processing, Post-Translational
  • Protein Stability

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: