Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
Mol Biol Cell. 2003 Nov;14(11):4721-33. Epub 2003 Aug 7.

Significance of 14-3-3 self-dimerization for phosphorylation-dependent target binding.

Author information

  • 1Cardiovascular Research Institute, Division of Molecular Cardiology, The Texas A&M University System Health Science Center, College of Medicine, Temple, Texas 76504, USA.

Abstract

14-3-3 proteins via binding serine/threonine-phosphorylated proteins regulate diverse intracellular processes in all eukaryotic organisms. Here, we examine the role of 14-3-3 self-dimerization in target binding, and in the susceptibility of 14-3-3 to undergo phosphorylation. Using a phospho-specific antibody developed against a degenerated mode-1 14-3-3 binding motif (RSxpSxP), we demonstrate that most of the 14-3-3-associated proteins in COS-7 cells are phosphorylated on sites that react with this antibody. The binding of these phosphoproteins depends on 14-3-3 dimerization, inasmuch as proteins associated in vivo with a monomeric 14-3-3 form are not recognized by the phospho-specific antibody. The role of 14-3-3 dimerization in the phosphorylation-dependent target binding is further exemplified with two well-defined 14-3-3 targets, Raf and DAF-16. Raf and DAF-16 can bind both monomeric and dimeric 14-3-3; however, whereas phosphorylation of specific Raf and DAF-16 sites is required for binding to dimeric 14-3-3, binding to monomeric 14-3-3 forms is entirely independent of Raf and DAF-16 phosphorylation. We also find that dimerization diminishes 14-3-3 susceptibility to phosphorylation. These findings establish a significant role of 14-3-3 dimerization in its ability to bind targets in a phosphorylation-dependent manner and point to a mechanism in which 14-3-3 phosphorylation and dimerization counterregulate each other.

PMID:
14551260
[PubMed - indexed for MEDLINE]
PMCID:
PMC266786
Free PMC Article

Images from this publication.See all images (7)Free text

Figure 3.
Figure 6.
Figure 1.
Figure 2.
Figure 4.
Figure 5.
Figure 7.
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk