title: Cell polarity signaling: focus on polar auxin transport.
abstract: Polar auxin transport, which is required for the formation of auxin gradients and directional auxin flows that are critical for plant pattern formation, morphogenesis, and directional growth response to vectorial cues, is mediated by polarized sub-cellular distribution of PIN-FORMED Proteins (PINs, auxin efflux carriers), AUX1/AUX1-like proteins (auxin influx facilitators), and multidrug resistance P-glycoproteins (MDR/PGP). Polar localization of these proteins is controlled by both developmental and environmental cues. Recent studies have revealed cellular (endocytosis, transcytosis, and endosomal sorting and recycling) and molecular (PINOID kinase, protein phosphatase 2A) mechanisms underlying the polar distribution of these auxin transport proteins. Both TIR1-mediated auxin signaling and TIR1-independent auxin-mediated endocytosis have been shown to regulate polar PIN localization and auxin flow, implicating auxin as a self-organizing signal in directing polar transport and directional flows.
authors.affiliation: Lanzhou University, Lanzhou 730000, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Gao
authors.forename: Shingo
authors.initials: S
authors.lastname: Nagawa
authors.forename: Genxuan
authors.initials: G
authors.lastname: Wang
authors.forename: Zhenbiao
authors.initials: Z
authors.lastname: Yang
mesh_terms: D001692:Biological Transport; D016764:Cell Polarity; D007210:Indoleacetic Acids / Q000378:metabolism*; D059828:Plant Cells; D010944:Plants / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D007210:Indoleacetic Acids