3 research outputs found
Regulation of the Arabidopsis AGC kinase PINOID by PDK1 and the microtubule cytoskeleton
Plants, are sessile
organisms, have developed strategies to adapt to changes in their environment,
in part by altering their growth and development. One of the central regulators
of this adaptive plant growth and development is the plant hormone auxin. Auxin
is transported by the PIN class of proteins. PIN proteins are membrane
localized proteins that transport auxin through the membrane. Plasma membrane
localized PIN proteins often show a polarized localization that is regulated by
the the AGC kinase PINOID.
We investigated the regulation of the PINOID kinase by
phosphoinositide-dependent protein kinase 1 (PDK1), a central upstream
regulator of AGC kinases. Here we show in arabidopsis protoplasts that PDK1
phosphorylation induces a switch in PINOID subcellular localization from the
plasma membrane to endomembrane compartments and the microtubule cytoskeleton
(MT). Our results in planta suggest a new role for dynamic PDK1-mediated
activation of PINOID in plant development. We reveal a regulatory complex that on
the one hand links PINOID to a dynamic process in young tissues that requires
high protein turnover and the MT. On the other hand, the complex is not
essential for survival and allows much variability within the involved kinesin
sequences between plant species. Plant science