Role of salt bridges in the dimer interface of 14-3-3zeta in dimer dynamics, N-terminal alpha-helical order, and molecular chaperone activity

Woodcock, JM; Goodwin, KL; Sandow, JJ; Coolen, C; Perugini, MA; Webb, AI; Pitson, SM; Lopez, AF; Carver, JA

Author(s): Woodcock, JM; Goodwin, KL; Sandow, JJ; Coolen, C; Perugini, MA; Webb, AI; Pitson, SM; Lopez, AF; Carver, JA;
Details: Publication Year 2018-01-05,Volume 293,Issue #1,Page 89-99
Journal Title: Journal of Biological Chemistry
Publication Type: Journal Article
Abstract: The 14-3-3 family of intracellular proteins are dimeric, multifunctional adaptor proteins that bind to and regulate the activities of many important signaling proteins. The subunits within 14-3-3 dimers are predicted to be stabilized by salt bridges that are largely conserved across the 14-3-3 protein family and allow the different isoforms to form heterodimers. Here, we have examined the contributions of conserved salt-bridging residues in stabilizing the dimeric state of 14-3-3zeta. Using analytical ultracentrifugation, our results revealed that Asp(21) and Glu(89) both play key roles in dimer dynamics and contribute to dimer stability. Furthermore, hydrogen-deuterium exchange coupled with mass spectrometry showed that mutation of Asp(21) promoted disorder in the N-terminal helices of 14-3-3zeta, suggesting that this residue plays an important role in maintaining structure across the dimer interface. Intriguingly, a D21N 14-3-3zeta mutant exhibited enhanced molecular chaperone ability that prevented amorphous protein aggregation, suggesting a potential role for N-terminal disorder in 14-3-3zeta's poorly understood chaperone action. Taken together, these results imply that disorder in the N-terminal helices of 14-3-3zeta is a consequence of the dimer-monomer dynamics and may play a role in conferring chaperone function to 14-3-3zeta protein.
Publisher: ASBMB
Research Division(s): Systems Biology And Personalised Medicine
PubMed ID: 29109150
Publisher's Version: https://doi.org/10.1074/jbc.M117.801019
NHMRC Grants: NHMRC/1068087, NHMRC/1071897, NHMRC/1042589, NHMRC/1068087, NHMRC/1071897,
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2018-02-14 04:25:24

Last Modified: 2019-06-17 03:05:36