Plant and Cell Physiology Advance Access published online on April 17, 2006
Plant and Cell Physiology, doi:10.1093/pcp/pcj050
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 USDA-ARS, and Department of Crop Science, North Carolina State University, Raleigh, NC 27695-7631; Present address: Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695-7622
* To whom correspondence should be addressed. The binding of 14-3-3
Received February 17, 2006
Accepted April 6, 2006
Regular Paper
Polycations Globally Enhance Binding of 14-3-3 Omega to Target Proteins in Spinach Leaves
Wei Shen 1
and
Steven C. Huber 2 *
2 USDA-ARS, and Department of Crop Science, North Carolina State University, Raleigh, NC 27695-7631; Present address: USDA-ARS, and Departments of Plant Biology and Crop Science, University of Illinois, Urbana, IL 61801-3838
Steven C. Huber, E-mail: schuber1{at}life.uiuc.edu
Abstract 
to phosphorylated NR (pNR) is stimulated by cations such as Mg2+ or spermine, and decreased by 5'-AMP. In order to determine whether binding to other cellular proteins is affected similarly, Far-Western overlays of extracts prepared from light- or dark-treated spinach (Spinacia oleracea) leaves were performed using digoxygenin (DIG)-labeled Arabidopsis 14-3-3. When separated by SDS-PAGE, approximately 25 proteins greater than 35 kDa could be resolved that interacted with DIG-labeled 14-3-3 in the absence of added cations. The presence of 5 mM Mg2+ or 0.5 mM spermine enhanced binding to most of the target proteins to a maximum of about a doubling of the observed binding. In most cases, the binding was dependent on phosphorylation of the target protein, whereas that was not necessarily the case for binding to target proteins that were unaffected by polycations. The extent of stimulation varied among the target proteins but there was no indication that the nature of the cation activator (e.g., Mg2+ versus spermine4+) altered the specificity for target proteins. In addition, binding of DIG-labeled 14-3-3 to some, but not all, target proteins was reduced by 5 mM 5'-AMP. Interestingly, light-dark treatment of spinach leaves affected the subsequent binding of DIG-labeled 14-3-3 in the overlay assay to only a few of the target proteins, one of which was identified as NADH:nitrate reductase. Overall, the results suggest that the binding of 14-3-3s to targets in addition to pNR may also be regulated by polycations and 5'-AMP.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  A. Garufi, S. Visconti, L. Camoni, and P. Aducci Polyamines as Physiological Regulators of 14-3-3 Interaction with the Plant Plasma Membrane H+-ATPase Plant Cell Physiol., March 1, 2007; 48(3): 434 - 440. [Abstract] [Full Text] [PDF]
|
|