ABP1 and ROP6 GTPase signaling regulate clathrin-mediated endocytosis in Arabidopsis roots.
The dynamic spatial and temporal distribution of the crucial plant signaling molecule auxin is achieved by feedback coordination of auxin signaling and intercellular auxin transport pathways. Developmental roles of auxin have been attributed predominantly to its effect on transcription; however, an alternative pathway involving AUXIN BINDING PROTEIN1 (ABP1) has been proposed to regulate clathrin-mediated endocytosis in roots and Rho-like GTPase (ROP)-dependent pavement cell interdigitation in leaves. In this study, we show that ROP6 and its downstream effector RIC1 regulate clathrin association with the plasma membrane for clathrin-mediated endocytosis, as well as for its feedback regulation by auxin. Genetic analysis revealed that ROP6/RIC1 acts downstream of ABP1 to regulate endocytosis. This signaling circuit is also involved in the feedback regulation of PIN-FORMED 1 (PIN1) and PIN2 auxin transporters activity (via its constitutive endocytosis) and corresponding auxin transport-mediated processes, including root gravitropism and leave vascular tissue patterning. Our findings suggest that the signaling module auxin-ABP1-ROP6/RIC1-clathrin-PIN1/PIN2 is a shared component of the feedback regulation of auxin transport during both root and aerial development.
Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium.
Xu
X
Chen
Satoshi
S
Naramoto
Stéphanie
S
Robert
Ricardo
R
Tejos
Christian
C
Löfke
Deshu
D
Lin
Zhenbiao
Z
Yang
Jiří
J
Friml
D017360:Arabidopsis / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D020126:Brefeldin A / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002966:Clathrin / Q000378:metabolism*; D004705:Endocytosis; D019204:GTP-Binding Proteins / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D018517:Plant Roots / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D015398:Signal Transduction
D029681:Arabidopsis Proteins; D020126:Brefeldin A; D002966:Clathrin; D019204:GTP-Binding Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; D020559:Monomeric GTP-Binding Proteins; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C116363:PIN1 protein, Arabidopsis; C117013:AT5G57090 protein, Arabidopsis; C518506:ROP6 protein, Arabidopsis; C083846:auxin-binding protein 1