The growing story of (ARABIDOPSIS) CRINKLY 4

Receptor kinases play important roles in plant growth and development, but only few of them have been functionally characterized in depth. Over the past decade CRINKLY 4 (CR4)-related research has peaked as a result of a newly discovered role of ARABIDOPSIS CR4 (ACR4) in the root. Here, we comprehensively review the available (A)CR4 literature and describe its role in embryo, seed, shoot, and root development, but we also flag an unexpected role in plant defence. In addition, we discuss ACR4 domains and protein structure, describe known ACR4-interacting proteins and substrates, and elaborate on the transcriptional regulation of ACR4. Finally, we address the missing knowledge in our understanding of ACR4 signalling

Molecular mobility in comb-like copolymethacrylates with chalcone-containing side-chains

[EN] The molecular mobility of comb-like copolymers of amyl methacrylate with N-methacryloyl-(4-amino-4'-bromochalcone) with various concentrations (20, 30, 40, 50 and 60 mol%) of chalcone-containing comonomer was studied using dielectric spectroscopy. It was found that chalcone chromophores participate in two forms of molecular mobility: cooperative motion in the rubbery state (delta-relaxation) and local motion in the glassy state (beta-relaxation). In addition, alpha-, beta(1)- and gamma-processes, being related to cooperative segmental mobility, to local motion of ester groups adjacent to the backbone and to local motion of terminal side-groups, respectively, were evident. The molecular mobility of the beta(1)-, beta-and gamma-processes changed slightly with the concentration of chromophore groups. For the delta- and alpha-processes, the glass transition temperatures, T(delta) and T(g), increased with the molar fraction of chalcone groups, the difference between them remaining nearly constant (ca 55 degrees C). The Td values obtained should be considered as optimal temperatures for the corona-poling of the chromophore-containing polymers for the preparation of second-order nonlinear optical polymer films with non-centrosymmetric arrangement of chromophore groups. (C) 2011 Society of Chemical IndustryThis research was supported by a grant of the Polytechnic University of Valencia (resolution of UPV from 13.05.08) and a grant of CICYT (MAt2008-06725-C03-03).Nikonorova, NA.; Díaz Calleja, R.; Yakimansky, AV. (2011). Molecular mobility in comb-like copolymethacrylates with chalcone-containing side-chains. Polymer International. 60(8):1215-1221. https://doi.org/10.1002/pi.3065S1215122160

PP2A-3 interacts with ACR4 and regulates formative cell division in the Arabidopsis root

In plants, the generation of new cell types and tissues depends on coordinated and oriented formative cell divisions. The plasma membrane-localized receptor kinase ARABIDOPSIS CRINKLY 4 (ACR4) is part of a mechanism controlling formative cell divisions in the Arabidopsis root. Despite its important role in plant development, very little is known about the molecular mechanism with which ACR4 is affiliated and its network of interactions. Here, we used various complementary proteomic approaches to identify ACR4-interacting protein candidates that are likely regulators of formative cell divisions and that could pave the way to unraveling the molecular basis behind ACR4-mediated signaling. We identified PROTEIN PHOSPHATASE 2A-3 (PP2A-3), a catalytic subunit of PP2A holoenzymes, as a previously unidentified regulator of formative cell divisions and as one of the first described substrates of ACR4. Our in vitro data argue for the existence of a tight posttranslational regulation in the associated biochemical network through reciprocal regulation between ACR4 and PP2A-3 at the phosphorylation level

PP2A-3 interacts with ACR4 and regulates formative cell division in the Arabidopsis root

In plants, the generation of new cell types and tissues depends on coordinated and oriented formative cell divisions. The plasma membrane-localized receptor kinase ARABIDOPSIS CRINKLY 4 (ACR4) is part of a mechanism controlling formative cell divisions in the Arabidopsis root. Despite its important role in plant development, very little is known about the molecular mechanism with which ACR4 is affiliated and its network of interactions. Here, we used various complementary proteomic approaches to identify ACR4-interacting protein candidates that are likely regulators of formative cell divisions and that could pave the way to unraveling the molecular basis behind ACR4-mediated signaling. We identified PROTEIN PHOSPHATASE 2A-3 (PP2A-3), a catalytic subunit of PP2A holoenzymes, as a previously unidentified regulator of formative cell divisions and as one of the first described substrates of ACR4. Our in vitro data argue for the existence of a tight posttranslational regulation in the associated biochemical network through reciprocal regulation between ACR4 and PP2A-3 at the phosphorylation level