In:
Frontiers in Plant Science, Frontiers Media SA, Vol. 12 ( 2021-10-14)
Kurzfassung:
Phytochrome activity is not only controlled by light but also by post-translational modifications, e. g. phosphorylation. One of the phosphatases responsible for plant phytochrome dephosphorylation and thereby increased activity is the phytochrome-associated protein phosphatase 5 (PAPP5). We show that PAPP5 recognizes phospho-site mimicking mutants of phytochrome B, when being activated by arachidonic acid (AA). Addition of AA to PAPP5 decreases the α-helical content as tracked by CD-spectroscopy. These changes correspond to conformational changes of the regulatory tetratricopeptide repeats (TPR) region as shown by mapping data from hydrogen deuterium exchange mass spectrometry onto a 3.0 Å crystal structure of PAPP5. Surprisingly, parts of the linker between the TPR and PP2A domains and of the so-called C-terminal inhibitory motif exhibit reduced deuterium uptake upon AA-binding. Molecular dynamics analyses of PAPP5 complexed to a phyB phosphopeptide show that this C-terminal motif remains associated with the TPR region in the substrate bound state, suggesting that this motif merely serves for restricting the orientations of the TPR region relative to the catalytic PP2A domain. Given the high similarity to mammalian PP5 these data from a plant ortholog show that the activation mode of these PPP-type protein phosphatases is highly conserved.
Materialart:
Online-Ressource
ISSN:
1664-462X
DOI:
10.3389/fpls.2021.733069
DOI:
10.3389/fpls.2021.733069.s001
DOI:
10.3389/fpls.2021.733069.s002
DOI:
10.3389/fpls.2021.733069.s003
DOI:
10.3389/fpls.2021.733069.s004
DOI:
10.3389/fpls.2021.733069.s005
Sprache:
Unbekannt
Verlag:
Frontiers Media SA
Publikationsdatum:
2021
ZDB Id:
2687947-5
ZDB Id:
2613694-6
