The plasma membrane recycling pathway and cell polarity in plants: studies on PIN proteins.
The PIN-FORMED (PIN) proteins are plasma-membrane-associated facilitators of auxin transport. They are often targeted to one side of the cell only through subcellular mechanisms that remain largely unknown. Here, we have studied the potential roles of the cytoskeleton and endomembrane system in the localisation of PIN proteins. Immunocytochemistry and image analysis on root cells from Arabidopsis thaliana and maize showed that 10-30% of the intracellular PIN proteins mapped to the Golgi network, but never to prevacuolar compartments. The remaining 70-90% were associated with yet to be identified structures. The maintenance of PIN proteins at the plasma membrane depends on a BFA-sensitive machinery, but not on microtubules and actin filaments. The polar localisation of PIN proteins at the plasmamembrane was not reflected by any asymmetric distribution of cytoplasmic organelles. In addition, PIN proteins were inserted in a symmetrical manner at both sides of the cell plate during cytokinesis. Together, the data indicate that the localisation of PIN proteins is a postmitotic event, which depends on local characteristics of the plasma membrane and its direct environment. In this context, we present evidence that microtubule arrays might define essential positional information for PIN localisation. This information seems to require the presence of an intact cell wall.
Boutté
Yohann
Y
Laboratoire de Dynamique de la Compartimentation Cellulaire, Institut des Sciences du Végétal, CNRS UPR2355, 9 Gif-sur-Yvette CEDEX, France.
Crosnier
Marie-Thérèse
MT
Carraro
Nicola
N
Traas
Jan
J
Satiat-Jeunemaitre
Béatrice
B
D017360:Arabidopsis / Q000033:anatomy & histology / Q000166:cytology / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D020126:Brefeldin A / Q000494:pharmacology; D002232:Carbocyanines; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D016764:Cell Polarity; D004305:Dose-Response Relationship, Drug; D016650:Fluorescein-5-isothiocyanate; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D008954:Models, Biological; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000166:cytology / Q000187:drug effects; D003313:Zea mays / Q000166:cytology / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
D029681:Arabidopsis Proteins; D002232:Carbocyanines; D005456:Fluorescent Dyes; D010940:Plant Proteins; C089187:cyanine dye 3; D020126:Brefeldin A; D016650:Fluorescein-5-isothiocyanate