Complex stability and dynamic subunit interchange modulates the disparate activities of the yeast moonlighting proteins Hal3 and Vhs3
Date
2015-10
Journal Title
Journal ISSN
Volume Title
Publisher
Springer Nature
Abstract
Saccharomyces cerevisiae Hal3 and Vhs3 are moonlighting proteins, acting both as inhibitors of
the serine/threonine protein phosphatase Ppz1 and as subunits (together with Cab3) of the unique
heterotrimeric phosphopantothenoylcysteine decarboxylase (PPCDC) enzyme of Hemiascomycetous
yeast. Both these roles are essential: PPCDC catalyses the third step of coenzyme A biosynthesis,
while Ppz1 inhibition is required for regulation of monovalent cation homeostasis. However, the
mechanisms by which these proteins’ disparate activities are regulated are not well understood.
The PPCDC domains (PDs) of Hal3, Vhs3 and Cab3 constitute the minimum requirement for these
proteins to show both PPCDC activity and, in the case of Hal3 and Vhs3, to bind to Ppz1. Using
these PD proteins as a model system to study the possibility of dynamic interchange between these
roles, we provide evidence that Hal3 binds Ppz1 as a monomer (1:1 stoichiometry), requiring it to deoligomerize
from its usual homo- and heterotrimeric states (the latter having PPCDC activity). This
de-oligomerization is made possible by structural features that set Hal3 apart from Vhs3, increasing
its ability to undergo monomer exchange. These findings suggest that oligomer interchange may
be a significant factor in the functional regulation of these proteins and their various unrelated
(moonlighting) functions.
Description
CITATION: Abrie, J. A., Molero, C., Arino, J. & Strauss, E. 2015. Complex stability and dynamic subunit interchange modulates the disparate activities of the yeast moonlighting proteins Hal3 and Vhs3. Scientific Reports, 5:15774, doi:10.1038/srep15774.
The original publication is available at http://www.nature.com/srep
The original publication is available at http://www.nature.com/srep
Keywords
Saccharomyces cerevisiae, Yeast moonlighting proteins
Citation
Abrie, J. A., Molero, C., Arino, J. & Strauss, E. 2015. Complex stability and dynamic subunit interchange modulates the disparate activities of the yeast moonlighting proteins Hal3 and Vhs3. Scientific Reports, 5:15774, doi:10.1038/srep15774.