The calcium-dependent protein kinase CPK7 acts on root hydraulic conductivity
2015
Li, Guowei | Boudsocq, Marie | Hem, Sonia | Vialaret, Jérôme | Rossignol, Michel | Maurel, Christophe | Biochimie et Physiologie Moléculaire des Plantes (BPMP) ; Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro) | Bio-Tech Research Center ; Shandong Academy of Agricultural Sciences (SAAS) | Institut des Sciences des Plantes de Paris-Saclay (IPS2 (UMR_9213 / UMR_1403)) ; Institut National de la Recherche Agronomique (INRA)-Université Paris-Sud - Paris 11 (UP11)-Université Paris Diderot - Paris 7 (UPD7)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS) | Unité de Recherche Protéomique (PROTEOMIQUE) ; Institut National de la Recherche Agronomique (INRA) | CHU Montpellier = Montpellier University Hospital ; Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier)
International audience
显示更多 [+] 显示较少 [-]英语. The hydraulic conductivity of plant roots (Lpr ) is determined in large part by the activity of aquaporins. Mechanisms occurring at the post-translational level, in particular phosphorylation of aquaporins of the plasma membrane intrinsic protein 2 (PIP2) subfamily, are thought to be of critical importance for regulating root water transport. However, knowledge of protein kinases and phosphatases acting on aquaporin function is still scarce. In the present work, we investigated the Lpr of knockout Arabidopsis plants for four Ca(2+) -dependent protein kinases. cpk7 plants showed a 30% increase in Lpr because of a higher aquaporin activity. A quantitative proteomic analysis of wild-type and cpk7 plants revealed that PIP gene expression and PIP protein quantity were not correlated and that CPK7 has no effect on PIP2 phosphorylation. In contrast, CPK7 exerts a negative control on the cellular abundance of PIP1s, which likely accounts for the higher Lpr of cpk7. In addition, this study revealed that the cellular amount of a few additional proteins including membrane transporters is controlled by CPK7. The overall work provides evidence for CPK7-dependent stability of specific membrane proteins.
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