TY  - JOUR
A1  - Majda, Mateusz
A1  - Grones, Peter
A1  - Sintorn, Ida-Maria
A1  - Vain, Thomas
A1  - Milani, Pascale
A1  - Krupinski, Pawel
A1  - Zagorska-Marek, Beata
A1  - Viotti, Corrado
A1  - Jonsson, Henrik
A1  - Mellerowicz, Ewa J.
A1  - Hamant, Olivier
A1  - Robert, Stephanie
T1  - Mechanochemical Polarization of Contiguous Cell Walls Shapes Plant Pavement Cells
JF  - Developmental cell
N2  - The epidermis of aerial plant organs is thought to be limiting for growth, because it acts as a continuous load-bearing layer, resisting tension. Leaf epidermis contains jigsaw puzzle piece-shaped pavement cells whose shape has been proposed to be a result of subcellular variations in expansion rate that induce local buckling events. Paradoxically, such local compressive buckling should not occur given the tensile stresses across the epidermis. Using computational modeling, we show that the simplest scenario to explain pavement cell shapes within an epidermis under tension must involve mechanical wall heterogeneities across and along the anticlinal pavement cell walls between adjacent cells. Combining genetics, atomic force microscopy, and immunolabeling, we demonstrate that contiguous cell walls indeed exhibit hybrid mechanochemical properties. Such biochemical wall heterogeneities precede wall bending. Altogether, this provides a possible mechanism for the generation of complex plant cell shapes.
Y1  - 2017
U6  - https://doi.org/10.1016/j.devcel.2017.10.017
SN  - 1534-5807
SN  - 1878-1551
VL  - 43
SP  - 290
EP  - +
PB  - Cell Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Liu, Qinsong
A1  - Vain, Thomas
A1  - Viotti, Corrado
A1  - Doyle, Siamsa M.
A1  - Tarkowska, Danuse
A1  - Novak, Ondrej
A1  - Zipfel, Cyril
A1  - Sitbon, Folke
A1  - Robert, Stephanie
A1  - Hofius, Daniel
T1  - Vacuole integrity maintained by DUF300 proteins is required for brassinosteroid signaling regulation
JF  - Molecular plant
N2  - Brassinosteroid (BR) hormone signaling controls multiple processes during plant growth and development and is initiated at the plasma membrane through the receptor kinase BRASSINOSTEROID INSENSITIVE1 (BRI1) together with co-receptors such as BRI1-ASSOCIATED RECEPTOR KINASE1 (BAK1). BRI1 abundance is regulated by endosomal recycling and vacuolar targeting, but the role of vacuole-related proteins in BR receptor dynamics and BR responses remains elusive. Here, we show that the absence of two DUF300 domain-containing tonoplast proteins, LAZARUS1 (LAZ1) and LAZ1 HOMOLOG1 (LAZ1H1), causes vacuole morphology defects, growth inhibition, and constitutive activation of BR signaling. Intriguingly, tonoplast accumulation of BAK1 was substantially increased and appeared causally linked to enhanced BRI1 trafficking and degradation in laz1 laz1h1 plants. Since unrelated vacuole mutants exhibited normal BR responses, our findings indicate that DUF300 proteins play distinct roles in the regulation of BR signaling by maintaining vacuole integrity required to balance subcellular BAK1 pools and BR receptor distribution.
KW  - brassinosteroid signaling
KW  - vacuole integrity
KW  - DUF300 proteins
KW  - tonoplast
KW  - Arabidopsis
Y1  - 2018
U6  - https://doi.org/10.1016/j.molp.2017.12.015
SN  - 1674-2052
SN  - 1752-9867
VL  - 11
IS  - 4
SP  - 553
EP  - 567
PB  - Cell Press
CY  - Cambridge
ER  - 
TY  - GEN
A1  - Mao, Hailiang
A1  - Nakamura, Moritaka
A1  - Viotti, Corrado
A1  - Grebe, Markus
T1  - A framework for lateral membrane trafficking and polar tethering of the PEN3 ATP-Binding cassette transporter
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - The outermost cell layer of plants, the epidermis, and its outer (lateral) membrane domain facing the environment are continuously challenged by biotic and abiotic stresses. Therefore, the epidermis and the outer membrane domain provide important selective and protective barriers. However, only a small number of specifically outer membrane-localized proteins are known. Similarly, molecular mechanisms underlying the trafficking and the polar placement of outer membrane domain proteins require further exploration. Here, we demonstrate that ACTIN7 (ACT7) mediates trafficking of the PENETRATION3 (PEN3) outer membrane protein from the trans-Golgi network (TGN) to the plasma membrane in the root epidermis of Arabidopsis (Arabidopsis thaliana) and that actin function contributes to PEN3 endocytic recycling. In contrast to such generic ACT7-dependent trafficking from the TGN, the EXOCYST84b (EXO84b) tethering factor mediates PEN3 outer-membrane polarity. Moreover, precise EXO84b placement at the outer membrane domain itself requires ACT7 function. Hence, our results uncover spatially and mechanistically distinct requirements for ACT7 function during outer lateral membrane cargo trafficking and polarity establishment. They further identify an exocyst tethering complex mediator of outer lateral membrane cargo polarity.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 909 
KW  - precursor indole-3-butyric acid
KW  - GNOM ARF-GEF
KW  - plasma-membrane
KW  - exocyst complex
KW  - auxin transport
KW  - planar polarity
KW  - Arabidopsis-thaliana
KW  - fluorescent protein
KW  - soil interface
KW  - cell polarity
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-441302
SN  - 1866-8372
IS  - 909
SP  - 2245
EP  - 2260
ER  - 
TY  - GEN
A1  - Nakamura, Moritaka
A1  - Claes, Andrea R.
A1  - Grebe, Tobias
A1  - Hermkes, Rebecca
A1  - Viotti, Corrado
A1  - Ikeda, Yoshihisa
A1  - Grebe, Markus
T1  - Auxin and ROP GTPase signaling of polar nuclear migration in root epidermal hair cells
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Polar nuclear migration is crucial during the development of diverse eukaryotes. In plants, root hair growth requires polar nuclear migration into the outgrowing hair. However, knowledge about the dynamics and the regulatory mechanisms underlying nuclear movements in root epidermal cells remains limited. Here, we show that both auxin and Rho-of-Plant (ROP) signaling modulate polar nuclear position at the inner epidermal plasma membrane domain oriented to the cortical cells during cell elongation as well as subsequent polar nuclear movement to the outer domain into the emerging hair bulge in Arabidopsis (Arabidopsis thaliana). Auxin signaling via the nuclear AUXIN RESPONSE FACTOR7 (ARF7)/ARF19 and INDOLE ACETIC ACID7 pathway ensures correct nuclear placement toward the inner membrane domain. Moreover, precise inner nuclear placement relies on SPIKE1 Rho-GEF, SUPERCENTIPEDE1 Rho-GDI, and ACTIN7 (ACT7) function and to a lesser extent on VTI11 vacuolar SNARE activity. Strikingly, the directionality and/or velocity of outer polar nuclear migration into the hair outgrowth along actin strands also are ACT7 dependent, auxin sensitive, and regulated by ROP signaling. Thus, our findings provide a founding framework revealing auxin and ROP signaling of inner polar nuclear position with some contribution by vacuolar morphology and of actin-dependent outer polar nuclear migration in root epidermal hair cells.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 992 
KW  - Arabidopsis-thaliana
KW  - planar polarity
KW  - tip growth
KW  - morphogenesis
KW  - gene
KW  - proteins
KW  - dynamics
KW  - transformation
KW  - activation
KW  - initiation
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-441278
SN  - 1866-8372
IS  - 992
SP  - 378
EP  - 391
ER  - 
TY  - JOUR
A1  - Nakamura, Moritaka
A1  - Claes, Andrea R.
A1  - Grebe, Tobias
A1  - Hermkes, Rebecca
A1  - Viotti, Corrado
A1  - Ikeda, Yoshihisa
A1  - Grebe, Markus
T1  - Auxin and ROP GTPase Signaling of Polar Nuclear Migration in Root Epidermal Hair Cells
JF  - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants
N2  - Polar nuclear migration is crucial during the development of diverse eukaryotes. In plants, root hair growth requires polar nuclear migration into the outgrowing hair. However, knowledge about the dynamics and the regulatory mechanisms underlying nuclear movements in root epidermal cells remains limited. Here, we show that both auxin and Rho-of-Plant (ROP) signaling modulate polar nuclear position at the inner epidermal plasma membrane domain oriented to the cortical cells during cell elongation as well as subsequent polar nuclear movement to the outer domain into the emerging hair bulge in Arabidopsis (Arabidopsis thaliana). Auxin signaling via the nuclear AUXIN RESPONSE FACTOR7 (ARF7)/ARF19 and INDOLE ACETIC ACID7 pathway ensures correct nuclear placement toward the inner membrane domain. Moreover, precise inner nuclear placement relies on SPIKE1 Rho-GEF, SUPERCENTIPEDE1 Rho-GDI, and ACTIN7 (ACT7) function and to a lesser extent on VTI11 vacuolar SNARE activity. Strikingly, the directionality and/or velocity of outer polar nuclear migration into the hair outgrowth along actin strands also are ACT7 dependent, auxin sensitive, and regulated by ROP signaling. Thus, our findings provide a founding framework revealing auxin and ROP signaling of inner polar nuclear position with some contribution by vacuolar morphology and of actin-dependent outer polar nuclear migration in root epidermal hair cells.
Y1  - 2017
U6  - https://doi.org/10.1104/pp.17.00713
SN  - 0032-0889
SN  - 1532-2548
VL  - 176
IS  - 1
SP  - 378
EP  - 391
PB  - American Society of Plant Physiologists
CY  - Rockville
ER  - 
TY  - JOUR
A1  - Mao, Hailiang
A1  - Nakamura, Moritaka
A1  - Viotti, Corrado
A1  - Grebe, Markus
T1  - A Framework for Lateral Membrane Trafficking and Polar Tethering of the PEN3 ATP-Binding Cassette Transporter
JF  - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants
N2  - The outermost cell layer of plants, the epidermis, and its outer (lateral) membrane domain facing the environment are continuously challenged by biotic and abiotic stresses. Therefore, the epidermis and the outer membrane domain provide important selective and protective barriers. However, only a small number of specifically outer membrane-localized proteins are known. Similarly, molecular mechanisms underlying the trafficking and the polar placement of outer membrane domain proteins require further exploration. Here, we demonstrate that ACTIN7 (ACT7) mediates trafficking of the PENETRATION3 (PEN3) outer membrane protein from the trans-Golgi network (TGN) to the plasma membrane in the root epidermis of Arabidopsis (Arabidopsis thaliana) and that actin function contributes to PEN3 endocytic recycling. In contrast to such generic ACT7-dependent trafficking from the TGN, the EXOCYST84b (EXO84b) tethering factor mediates PEN3 outer-membrane polarity. Moreover, precise EXO84b placement at the outer membrane domain itself requires ACT7 function. Hence, our results uncover spatially and mechanistically distinct requirements for ACT7 function during outer lateral membrane cargo trafficking and polarity establishment. They further identify an exocyst tethering complex mediator of outer lateral membrane cargo polarity.
Y1  - 2016
U6  - https://doi.org/10.1104/pp.16.01252
SN  - 0032-0889
SN  - 1532-2548
VL  - 172
SP  - 2245
EP  - 2260
PB  - American Society of Plant Physiologists
CY  - Rockville
ER  - 
TY  - JOUR
A1  - Dejonghe, Wim
A1  - Kuenen, Sabine
A1  - Mylle, Evelien
A1  - Vasileva, Mina
A1  - Keech, Olivier
A1  - Viotti, Corrado
A1  - Swerts, Jef
A1  - Fendrych, Matyas
A1  - Ortiz-Morea, Fausto Andres
A1  - Mishev, Kiril
A1  - Delang, Simon
A1  - Scholl, Stefan
A1  - Zarza, Xavier
A1  - Heilmann, Mareike
A1  - Kourelis, Jiorgos
A1  - Kasprowicz, Jaroslaw
A1  - Nguyen, Le Son Long
A1  - Drozdzecki, Andrzej
A1  - Van Houtte, Isabelle
A1  - Szatmari, Anna-Maria
A1  - Majda, Mateusz
A1  - Baisa, Gary
A1  - Bednarek, Sebastian York
A1  - Robert, Stephanie
A1  - Audenaert, Dominique
A1  - Testerink, Christa
A1  - Munnik, Teun
A1  - Van Damme, Daniel
A1  - Heilmann, Ingo
A1  - Schumacher, Karin
A1  - Winne, Johan
A1  - Friml, Jiri
A1  - Verstreken, Patrik
A1  - Russinova, Eugenia
T1  - Mitochondrial uncouplers inhibit clathrin-mediated endocytosis largely through cytoplasmic acidification
JF  - Nature Communications
N2  - ATP production requires the establishment of an electrochemical proton gradient across the inner mitochondrial membrane. Mitochondrial uncouplers dissipate this proton gradient and disrupt numerous cellular processes, including vesicular trafficking, mainly through energy depletion. Here we show that Endosidin9 (ES9), a novel mitochondrial uncoupler, is a potent inhibitor of clathrin-mediated endocytosis (CME) in different systems and that ES9 induces inhibition of CME not because of its effect on cellular ATP, but rather due to its protonophore activity that leads to cytoplasm acidification. We show that the known tyrosine kinase inhibitor tyrphostinA23, which is routinely used to block CME, displays similar properties, thus questioning its use as a specific inhibitor of cargo recognition by the AP-2 adaptor complex via tyrosine motif-based endocytosis signals. Furthermore, we show that cytoplasm acidification dramatically affects the dynamics and recruitment of clathrin and associated adaptors, and leads to reduction of phosphatidylinositol 4,5-biphosphate from the plasma membrane.
Y1  - 2016
U6  - https://doi.org/10.1038/ncomms11710
SN  - 2041-1723
VL  - 7
SP  - 1959
EP  - 1968
PB  - Nature Publ. Group
CY  - London
ER  -