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

Abstract

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.stem cells | columella | phosphorylation | kinase | phosphatase

Control of Arabidopsis lateral root primordium boundaries by MYB36

“…For example, the receptor kinase ACR4 acts at the very early stages of LRP formation to restrict anticlinal divisions of competent pericycle cells . It also works in the root apical meristem to control formative cell divisions (Yue et al, 2016).…”

Redox-Mediated Endocytosis of a Receptor-Like Kinase during Distal Stem Cell Differentiation Depends on Its Tumor Necrosis Factor Receptor Domain

“…ACR4 interacts with and phosphorylates PP2A-3 (a catalytic subunit of the PP2A holoenzyme), and PP2A dephosphorylates ACR4 to positively mediate its membrane localization (Yue et al, 2016). PP2A-3 and PP2A-4 redundantly mediate DSC differentiation and primary root growth (Yue et al, 2016). We therefore investigated whether these PP2As are involved in ROSmediated DSC differentiation.…”

“…The following mutants and/or transgenic plants were employed in this study: abo8-1 (Yang et al, 2014), pad2-1 (Parisy et al, 2007), atrbohD, atrbohF (Torres et al, 2002), asa1-1 (Sun et al, 2009), pin3-4 (Friml et al, 2003), tir1-1 afb1,2,3 (Parry et al, 2009), acr4-2, ProACR4:ACR4-GFP (Gifford et al, 2005), clv1-1 (Müller et al, 2008), wox5-1, Pro-35S:WOX5-GR, plt1-4, plt2-2, plt1-4 plt2-2, J2341 (De Tullio et al, 2010), ProPLT1:CFP, ProPLT2:CFP, ProPLT1:PLT1-YFP, ProPLT2:PLT2-YFP (Zhou et al, 2010), pp2a-3-1 (SALK_069250), pp2a-4 (SALK_035009), pp2a-3pp2a-4 (Yue et al, 2016), and pp2a-3-2 (SALK_115680), app1-1, app1-2 (Yu et al, 2016).…”

Crystal structures of Arabidopsis and Physcomitrella CR4 reveal the molecular architecture of CRINKLY4 receptor kinases

“…Similar observations have been made for CrRLK1L-family receptor kinases [50][51][52] . The mechanistic implications are poorly understood, but the involvement of protein phosphatases in both CR4 and CrRLK1L-mediated signal transduction 33,53,54 suggests that the cytoplasmic kinases domains of these receptors may act as scaffolding proteins that can become phosphorylated despite not requiring auto-and trans-phosphorylation activity themselves.…”

“…PROTEIN PHOSPHATASE 2A-3 (PP2A-3) and WOX5 have been identified as direct interaction partners for the ACR4 cytoplasmic domain 33,34 . Here, we uncover the architecture of plant-unique CRINKLY4 RKs by solving crystal structures of ACR4 and from Physcomitrella patens 35 PpCR4.…”