title: FYVE1/FREE1 Interacts with the PYL4 ABA Receptor and Mediates Its Delivery to the Vacuolar Degradation Pathway.
abstract: Recently, we described the ubiquitylation of PYL4 and PYR1 by the RING E3 ubiquitin ligase RSL1 at the plasma membrane ofArabidopsis thalianaThis suggested that ubiquitylated abscisic acid (ABA) receptors might be targeted to the vacuolar degradation pathway because such ubiquitylation is usually an internalization signal for the endocytic route. Here, we show that FYVE1 (previously termed FREE1), a recently described component of the endosomal sorting complex required for transport (ESCRT) machinery, interacted with RSL1-receptor complexes and recruited PYL4 to endosomal compartments. Although the ESCRT pathway has been assumed to be reserved for integral membrane proteins, we show the involvement of this pathway in the degradation of ABA receptors, which can be associated with membranes but are not integral membrane proteins. Knockdownfyve1alleles are hypersensitive to ABA, illustrating the biological relevance of the ESCRT pathway for the modulation of ABA signaling. In addition,fyve1mutants are impaired in the targeting of ABA receptors for vacuolar degradation, leading to increased accumulation of PYL4 and an enhanced response to ABA Pharmacological and genetic approaches revealed a dynamic turnover of ABA receptors from the plasma membrane to the endosomal/vacuolar degradation pathway, which was mediated by FYVE1 and was dependent on RSL1. This process involves clathrin-mediated endocytosis and trafficking of PYL4 through the ESCRT pathway, which helps to regulate the turnover of ABA receptors and attenuate ABA signaling.
authors: Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, 46022 Valencia, Spain.
authors: Borja
authors: B
authors: Belda-Palazon
authors: Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, 46022 Valencia, Spain.
authors: Lesia
authors: http://orcid.org/0000-0003-0601-6735
authors: L
authors: Rodriguez
authors: Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, 46022 Valencia, Spain.
authors: Maria A
authors: MA
authors: Fernandez
authors: Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, 46022 Valencia, Spain.
authors: Mari-Cruz
authors: http://orcid.org/0000-0002-9647-0896
authors: MC
authors: Castillo
authors: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors: Erin M
authors: EM
authors: Anderson
authors: Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China.
authors: Caiji
authors: C
authors: Gao
authors: Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, 46022 Valencia, Spain.
authors: Miguel
authors: http://orcid.org/0000-0003-1000-9255
authors: M
authors: Gonzalez-Guzman
authors: Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, 46022 Valencia, Spain.
authors: Marta
authors: M
authors: Peirats-Llobet
authors: Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China.
authors: Qiong
authors: http://orcid.org/0000-0003-4557-3139
authors: Q
authors: Zhao
authors: Department of Plant Systems Biology and Department of Plant Biotechnology and Bioinformatics, Vlaams Instituut voor Biotechnologie, Ghent University, B-9052 Ghent, Belgium.
authors: Nancy
authors: N
authors: De Winne
authors: Department of Medical Protein Research and Department of Biochemistry, Vlaams Instituut voor Biotechnologie, Ghent University, B-9000 Ghent, Belgium.
authors: Kris
authors: http://orcid.org/0000-0002-4237-0283
authors: K
authors: Gevaert
authors: Department of Plant Systems Biology and Department of Plant Biotechnology and Bioinformatics, Vlaams Instituut voor Biotechnologie, Ghent University, B-9052 Ghent, Belgium.
authors: Geert
authors: http://orcid.org/0000-0001-6558-5669
authors: G
authors: De Jaeger
authors: Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, China.
authors: Liwen
authors: L
authors: Jiang
authors: Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, 46022 Valencia, Spain.
authors: José
authors: http://orcid.org/0000-0002-7332-1572
authors: J
authors: León
authors: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
authors: Robert T
authors: http://orcid.org/0000-0002-6915-7407
authors: RT
authors: Mullen
authors: Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, 46022 Valencia, Spain prodriguez@ibmcp.upv.es.
authors: Pedro L
authors: http://orcid.org/0000-0002-5886-9425
authors: PL
authors: Rodriguez