Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Molecular Characterization of an Arabidopsis Gene Encoding a Phospholipid-Specific Inositol Polyphosphate 5-Phosphatase

Mustafa E. Ercetin and Glenda E. Gillaspy
Plant Physiology
Vol. 135, No. 2 (Jun., 2004), pp. 938-946
Stable URL: http://www.jstor.org/stable/4281813
Page Count: 9
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Molecular Characterization of an Arabidopsis Gene Encoding a Phospholipid-Specific Inositol Polyphosphate 5-Phosphatase
Preview not available

Abstract

Phosphoinositides are important molecules that serve as second messengers and bind to a complex array of proteins modulating their subcellular location and activity. The enzymes that metabolize phosphoinositides can in some cases serve to terminate the signaling actions of phosphoinositides. The inositol polyphosphate 5-phosphatases (5PTases) comprise a large protein family that hydrolyzes 5-phosphates from a variety of inositol phosphate and phosphoinositide substrates. We previously reported the identification of 15 putative 5PTase genes in Arabidopsis and have shown that overexpression of the At5PTase1 gene can alter abscisic acid signaling. At5PTase1 and At5PTase2 have been shown to hydrolyze the 5-phosphate from inositol phosphate substrates. We have examined the substrate specificity of the At5PTase11 protein, which is one of the smallest predicted 5PTases found in any organism. We report here that the At5PTase11 gene encodes an active 5PTase enzyme that can only dephosphorylate phosphoinositide substrates containing a 5-phosphate. In addition to hydrolyzing known substrates of 5PTase enzymes, At5PTase11 also hydrolyzes the 5-phosphate from phosphatidylinositol (3,5) bisphosphate. We also show that the At5PTase11 gene is regulated by abscisic acid, jasmonic acid, and auxin, suggesting a role for phosphoinositide action in these signal transduction pathways.

Page Thumbnails

  • Thumbnail: Page 
938
    938
  • Thumbnail: Page 
939
    939
  • Thumbnail: Page 
940
    940
  • Thumbnail: Page 
941
    941
  • Thumbnail: Page 
942
    942
  • Thumbnail: Page 
943
    943
  • Thumbnail: Page 
944
    944
  • Thumbnail: Page 
945
    945
  • Thumbnail: Page 
946
    946