TY  - JOUR
A1  - Robert, Helene S.
A1  - Grunewald, Wim
A1  - Sauer, Michael
A1  - Cannoot, Bernard
A1  - Soriano, Mercedes
A1  - Swarup, Ranjan
A1  - Weijers, Dolf
A1  - Bennett, Malcolm
A1  - Boutilier, Kim
A1  - Friml, Jiri
T1  - Plant embryogenesis requires AUX/LAX-mediated auxin influx
JF  - Development : Company of Biologists
N2  - The plant hormone auxin and its directional transport are known to play a crucial role in defining the embryonic axis and subsequent development of the body plan. Although the role of PIN auxin efflux transporters has been clearly assigned during embryonic shoot and root specification, the role of the auxin influx carriers AUX1 and LIKE-AUX1 (LAX) proteins is not well established. Here, we used chemical and genetic tools on Brassica napus microspore-derived embryos and Arabidopsis thaliana zygotic embryos, and demonstrate that AUX1, LAX1 and LAX2 are required for both shoot and root pole formation, in concert with PIN efflux carriers. Furthermore, we uncovered a positive-feedback loop between MONOPTEROS-(ARF5)dependent auxin signalling and auxin transport. This MONOPTEROS dependent transcriptional regulation of auxin influx (AUX1, LAX1 and LAX2) and auxin efflux (PIN1 and PIN4) carriers by MONOPTEROS helps to maintain proper auxin transport to the root tip. These results indicate that auxin-dependent cell specification during embryo development requires balanced auxin transport involving both influx and efflux mechanisms, and that this transport is maintained by a positive transcriptional feedback on auxin signalling.
KW  - Arabidopsis thaliana embryogenesis
KW  - Auxin transport
KW  - AUX1
KW  - LIKE-AUX1 (LAX)
KW  - MONOPTEROS (ARF5)
KW  - PIN
KW  - Brassica napus
KW  - Microspore
Y1  - 2015
U6  - https://doi.org/10.1242/dev.115832
SN  - 0950-1991
SN  - 1477-9129
VL  - 142
IS  - 4
SP  - 702
EP  - 711
PB  - Company of Biologists Limited
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Tejos, Ricardo
A1  - Rodriguez-Furlan, Cecilia
A1  - Adamowski, Maciej
A1  - Sauer, Michael
A1  - Norambuena, Lorena
A1  - Friml, Jiri
T1  - PATELLINS are regulators of auxin-mediated PIN1 relocation and plant development in Arabidopsis thaliana
JF  - Journal of cell science
N2  - Coordinated cell polarization in developing tissues is a recurrent theme in multicellular organisms. In plants, a directional distribution of the plant hormone auxin is at the core of many developmental programs. A feedback regulation of auxin on the polarized localization of PIN auxin transporters in individual cells has been proposed as a self-organizing mechanism for coordinated tissue polarization, but the molecular mechanisms linking auxin signalling to PIN-dependent auxin transport remain unknown. We used a microarray-based approach to find regulators of the auxin-induced PIN relocation in Arabidopsis thaliana root, and identified a subset of a family of phosphatidylinositol transfer proteins (PITPs), the PATELLINs (PATLs). Here, we show that PATLs are expressed in partially overlapping cell types in different tissues going through mitosis or initiating differentiation programs. PATLs are plasma membrane-associated proteins accumulated in Arabidopsis embryos, primary roots, lateral root primordia and developing stomata. Higher order patl mutants display reduced PIN1 repolarization in response to auxin, shorter root apical meristem, and drastic defects in embryo and seedling development. This suggests that PATLs play a redundant and crucial role in polarity and patterning in Arabidopsis.
KW  - PATELLIN
KW  - Auxin
KW  - Arabidopsis thaliana
KW  - Auxin transport
KW  - Canalization
Y1  - 2018
U6  - https://doi.org/10.1242/jcs.204198
SN  - 0021-9533
SN  - 1477-9137
VL  - 131
IS  - 2
PB  - Company of Biologists Limited
CY  - Cambridge
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  -