TY - JOUR ID - 2158 TI - The Arabidopsis ALF4 protein is a regulator of SCF E3 ligases. JO - EMBO J PY - 2018 SP - 255-268 AU - Bagchi, R. AU - Melnyk, C. W. AU - Christ, G. AU - Winkler, M. AU - Kirchsteiner, K. AU - Salehin, M. AU - Mergner, J. AU - Niemeyer, M. AU - Schwechheimer, C. AU - Calderón Villalobos, L. I. A. AU - Estelle, M. VL - 37 UR - http://onlinelibrary.wiley.com/doi/10.15252/embj.201797159/full DO - 10.15252/embj.201797159 AB - The cullin-RING E3 ligases (CRLs) regulate diverse cellular processes in all eukaryotes. CRL activity is controlled by several proteins or protein complexes, including NEDD8, CAND1, and the CSN. Recently, a mammalian protein called Glomulin (GLMN) was shown to inhibit CRLs by binding to the RING BOX (RBX1) subunit and preventing binding to the ubiquitin-conjugating enzyme. Here, we show that Arabidopsis ABERRANT LATERAL ROOT FORMATION4 (ALF4) is an ortholog of GLMN. The alf4 mutant exhibits a phenotype that suggests defects in plant hormone response. We show that ALF4 binds to RBX1 and inhibits the activity of SCFTIR1, an E3 ligase responsible for degradation of the Aux/IAA transcriptional repressors. In vivo, the alf4 mutation destabilizes the CUL1 subunit of the SCF. Reduced CUL1 levels are associated with increased levels of the Aux/IAA proteins as well as the DELLA repressors, substrate of SCFSLY1. We propose that the alf4 phenotype is partly due to increased levels of the Aux/IAA and DELLA proteins. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1304 TI - Phosphate sensing in root development JO - Curr Opin Plant Biol PY - 2011 SP - 303-309 AU - Abel, S. VL - 14 UR - https://dx.doi.org/10.1016/j.pbi.2011.04.007 DO - 10.1016/j.pbi.2011.04.007 AB - Phosphate (Pi) and its anhydrides constitute major nodes in metabolism. Thus, plant performance depends directly on Pi nutrition. Inadequate Pi availability in the rhizosphere is a common challenge to plants, which activate metabolic and developmental responses to maximize Pi usage and acquisition. The sensory mechanisms that monitor environmental Pi and transmit the nutritional signal to adjust root development have increasingly come into focus. Recent transcriptomic analyses and genetic approaches have highlighted complex antagonistic interactions between external Pi and Fe bioavailability and have implicated the stem cell niche as a target of Pi sensing to regulate root meristem activity. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 854 TI - Auxin signaling JO - Curr Opin Plant Biol PY - 2006 SP - 448-453 AU - Quint, M. AU - Gray, W.M. VL - 9 UR - DO - 10.1016/j.pbi.2006.07.006 AB - Auxin regulates a host of plant developmental and physiological processes, including embryogenesis, vascular differentiation, organogenesis, tropic growth, and root and shoot architecture. Genetic and biochemical studies carried out over the past decade have revealed that much of this regulation involves the SCFTIR1/AFB-mediated proteolysis of the Aux/IAA family of transcriptional regulators. With the recent finding that the TRANSPORT INHIBITOR RESPONSE1 (TIR1)/AUXIN SIGNALING F-BOX (AFB) proteins also function as auxin receptors, a potentially complete, and surprisingly simple, signaling pathway from perception to transcriptional response is now before us. However, understanding how this seemingly simple pathway controls the myriad of specific auxin responses remains a daunting challenge, and compelling evidence exists for SCFTIR1/AFB-independent auxin signaling pathways. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 353 TI - Heterologous expression and characterization of human glutaminyl cyclase: evidence for a disulfide bond with importance for catalytic activity JO - Biochemistry PY - 2002 SP - 10849-10857 AU - Schilling, S. AU - Hoffmann, T. AU - Rosche, F. AU - Manhart, S. AU - Wasternack, C. AU - Demuth, H.-U. VL - 41 UR - AB - A2 - C1 - Molecular Signal Processing ER -