TY - JOUR A1 - Zouhar, Jan A1 - Sauer, Michael T1 - Helping hands for budding prospects: ENTH/ANTH/VHS accessory proteins in endocytosis, vacuolar transport, and secretion JF - The plant cell N2 - Coated vesicles provide a major mechanism for the transport of proteins through the endomembrane system of plants. Transport between the endoplasmic reticulum and the Golgi involves vesicles with COPI and COPII coats, whereas clathrin is the predominant coat in endocytosis and post-Golgi trafficking. Sorting of cargo, coat assembly, budding, and fission are all complex and tightly regulated processes that involve many proteins. The mechanisms and responsible factors are largely conserved in eukaryotes, and increasing organismal complexity tends to be associated with a greater numbers of individual family members. Among the key factors is the class of ENTH/ANTH/VHS domain-containing proteins, which link membrane subdomains, clathrin, and other adapter proteins involved in early steps of clathrin coated vesicle formation. More than 30 Arabidopsis thaliana proteins contain this domain, but their generally low sequence conservation has made functional classification difficult. Reports from the last two years have greatly expanded our knowledge of these proteins and suggest that ENTH/ANTH/VHS domain proteins are involved in various instances of clathrin-related endomembrane trafficking in plants. This review aims to summarize these new findings and discuss the broader context of clathrin-dependent plant vesicular transport. Y1 - 2014 U6 - https://doi.org/10.1105/tpc.114.131680 SN - 1040-4651 SN - 1532-298X VL - 26 IS - 11 SP - 4232 EP - 4244 PB - American Society of Plant Physiologists CY - Rockville 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 - Sauer, Michael A1 - Kleine-Vehn, Jürgen T1 - PIN-FORMED and PIN-LIKES auxin transport facilitators JF - Development : Company of Biologists N2 - The phytohormone auxin influences virtually all aspects of plant growth and development. Auxin transport across membranes is facilitated by, among other proteins, members of the PIN-FORMED (PIN) and the structurally similar PIN-LIKES (PILS) families, which together govern directional cell-to-cell transport and intracellular accumulation of auxin. Canonical PIN proteins, which exhibit a polar localization in the plasma membrane, determine many patterning and directional growth responses. Conversely, the less-studied noncanonical PINs and PILS proteins, which mostly localize to the endoplasmic reticulum, attenuate cellular auxin responses. Here, and in the accompanying poster, we provide a brief summary of current knowledge of the structure, evolution, function and regulation of these auxin transport facilitators. KW - Auxin KW - Auxin transport KW - Phytohormone Y1 - 2019 U6 - https://doi.org/10.1242/dev.168088 SN - 0950-1991 SN - 1477-9129 VL - 146 IS - 15 PB - Company biologists ltd CY - Cambridge ER - TY - JOUR A1 - Sauer, Michael A1 - Grebe, Markus T1 - Plant cell biology BT - PIN polarity maintained JF - Current biology : CB N2 - PIN-FORMED (PIN) polar protein localization directs transport of the growth and developmental regulator auxin in plants. Once established after cytokinesis, PIN polarity requires maintenance. Now, direct interactions between PIN, MAB4/MEL and PID proteins suggest self-reinforced maintenance of PIN polarity through limiting lateral diffusion. Y1 - 2021 U6 - https://doi.org/10.1016/j.cub.2021.03.070 SN - 0960-9822 SN - 1879-0445 VL - 31 IS - 9 SP - R449 EP - R451 PB - Cell Press CY - Cambridge ER - 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 - GEN A1 - Prát, Tomáš A1 - Hajny ́, Jakub A1 - Grunewald, Wim A1 - Vasileva, Mina A1 - Molnár, Gergely A1 - Tejos, Ricardo A1 - Schmid, Markus A1 - Sauer, Michael A1 - Friml, Jiří T1 - WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Auxin is unique among plant hormones due to its directional transport that is mediated by the polarly distributed PIN auxin transporters at the plasma membrane. The canalization hypothesis proposes that the auxin feedback on its polar flow is a crucial, plant-specific mechanism mediating multiple self-organizing developmental processes. Here, we used the auxin effect on the PIN polar localization in Arabidopsis thaliana roots as a proxy for the auxin feedback on the PIN polarity during canalization. We performed microarray experiments to find regulators of this process that act downstream of auxin. We identified genes that were transcriptionally regulated by auxin in an AXR3/IAA17-and ARF7/ARF19-dependent manner. Besides the known components of the PIN polarity, such as PID and PIP5K kinases, a number of potential new regulators were detected, among which the WRKY23 transcription factor, which was characterized in more detail. Gain-and loss-of-function mutants confirmed a role for WRKY23 in mediating the auxin effect on the PIN polarity. Accordingly, processes requiring auxin-mediated PIN polarity rearrangements, such as vascular tissue development during leaf venation, showed a higher WRKY23 expression and required the WRKY23 activity. Our results provide initial insights into the auxin transcriptional network acting upstream of PIN polarization and, potentially, canalization-mediated plant development. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1123 KW - apical-basal axis KW - arabidopsis-thaliana KW - root gravitropism KW - DNA-binding KW - gene-expression KW - transport KW - efflux KW - canalization KW - plants KW - phosphorylation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-446331 SN - 1866-8372 IS - 1123 ER - TY - JOUR A1 - Prat, Tomas A1 - Hajny, Jakub A1 - Grunewald, Wim A1 - Vasileva, Mina A1 - Molnar, Gergely A1 - Tejos, Ricardo A1 - Schmid, Markus A1 - Sauer, Michael A1 - Friml, Jiří T1 - WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity JF - PLoS Genetics : a peer-reviewed, open-access journal N2 - Auxin is unique among plant hormones due to its directional transport that is mediated by the polarly distributed PIN auxin transporters at the plasma membrane. The canalization hypothesis proposes that the auxin feedback on its polar flow is a crucial, plant-specific mechanism mediating multiple self-organizing developmental processes. Here, we used the auxin effect on the PIN polar localization in Arabidopsis thaliana roots as a proxy for the auxin feedback on the PIN polarity during canalization. We performed microarray experiments to find regulators of this process that act downstream of auxin. We identified genes that were transcriptionally regulated by auxin in an AXR3/IAA17-and ARF7/ARF19-dependent manner. Besides the known components of the PIN polarity, such as PID and PIP5K kinases, a number of potential new regulators were detected, among which the WRKY23 transcription factor, which was characterized in more detail. Gain-and loss-of-function mutants confirmed a role for WRKY23 in mediating the auxin effect on the PIN polarity. Accordingly, processes requiring auxin-mediated PIN polarity rearrangements, such as vascular tissue development during leaf venation, showed a higher WRKY23 expression and required the WRKY23 activity. Our results provide initial insights into the auxin transcriptional network acting upstream of PIN polarization and, potentially, canalization-mediated plant development. Y1 - 2018 U6 - https://doi.org/10.1371/journal.pgen.1007177 SN - 1553-7404 VL - 14 IS - 1 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Muñoz, Alfonso A1 - Mangano, Silvina A1 - Paz Gonzalez-Garcia, Mary A1 - Contreras, Ramon A1 - Sauer, Michael A1 - De Rybel, Bert A1 - Weijers, Dolf A1 - Juan Sanchez-Serrano, Jose A1 - Sanmartin, Maite A1 - Rojo, Enrique T1 - RIMA-Dependent Nuclear Accumulation of IYO Triggers Auxin-Irreversible Cell Differentiation in Arabidopsis JF - The plant cell N2 - The transcriptional regulator MINIYO (IYO) is essential and rate-limiting for initiating cell differentiation in Arabidopsis thaliana. Moreover, IYO moves from the cytosol into the nucleus in cells at the meristem periphery, possibly triggering their differentiation. However, the genetic mechanisms controlling IYO nuclear accumulation were unknown, and the evidence that increased nuclear IYO levels trigger differentiation remained correlative. Searching for IYO interactors, we identified RPAP2 IYO Mate (RIMA), a homolog of yeast and human proteins linked to nuclear import of selective cargo. Knockdown of RIMA causes delayed onset of cell differentiation, phenocopying the effects of IYO knockdown at the transcriptomic and developmental levels. Moreover, differentiation is completely blocked when IYO and RIMA activities are simultaneously reduced and is synergistically accelerated when IYO and RIMA are concurrently overexpressed, confirming their functional interaction. Indeed, RIMA knockdown reduces the nuclear levels of IYO and prevents its prodifferentiation activity, supporting the conclusion that RIMA-dependent nuclear IYO accumulation triggers cell differentiation in Arabidopsis. Importantly, by analyzing the effect of the IYO/RIMA pathway on xylem pole pericycle cells, we provide compelling evidence reinforcing the view that the capacity for de novo organogenesis and regeneration from mature plant tissues can reside in stem cell reservoirs. Y1 - 0201 U6 - https://doi.org/10.1105/tpc.16.00791 SN - 1040-4651 SN - 1532-298X VL - 29 IS - 3 SP - 575 EP - 588 PB - American Society of Plant Physiologists CY - Rockville ER - TY - GEN A1 - Lechon, Tamara A1 - Sanz, Luis A1 - Pollmann, Stephan A1 - Sauer, Michael A1 - Sandalio, Luisa A1 - Lorenzo, Oscar T1 - Nitric oxide modification of plant endocytosis and PIN1 localization T2 - New biotechnology Y1 - 2016 U6 - https://doi.org/10.1016/j.nbt.2015.10.028 SN - 1871-6784 SN - 1876-4347 VL - 33 SP - 424 EP - 424 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Kleine-Vehn, Jürgen A1 - Sauer, Michael ED - Kleine-Vehn, Jürgen ED - Sauer, Michael T1 - Preface T2 - Plant Hormones: Methods and Protocols Y1 - 2017 SN - 978-1-4939-6469-7 SN - 978-1-4939-6467-3 U6 - https://doi.org/10.1007/978-1-4939-6469-7 SN - 1064-3745 SN - 1940-6029 VL - 1497 SP - V EP - V PB - Springer CY - New York ET - 3 ER -