title: Mastoparan alters subcellular distribution of profilin and remodels F-actin cytoskeleton in cells of maize root apices.
abstract: Indirect immunofluorescence localization of profilin in cells of maize root apices revealed that this abundant protein was present both in the cytoplasm and within nuclei. Nucleo-cytoplasmic partitioning of profilin exhibits tissue-specific and developmental features. Mastoparan-mediated activation of heterotrimeric G-proteins, presumably through triggering a phosphoinositide-signaling pathway based on phosphatidylinositol-4,5-bisphosphate (PIP(2)), induced relocalization of profilin from nuclei into the cytoplasm of root apex cells. In contrast, PIP(2) accumulated within nuclei of mastoparan-treated root cells. Intriguingly, cytoplasmic accumulation of profilin was associated with remodeling of F-actin arrays in root apex cells. Specifically, dense F-actin networks were dismantled and distinct actin patches became associated with the periphery of small vacuoles. On the other hand, disruption of F-actin with the G-actin sequestering agent latrunculin B does not affect the subcellular distribution of profilin or PIP(2). These data suggest that nuclear profilin can mediate a stimulus-response action on the actin cytoskeleton which is somehow linked to a phosphoinositide-signaling cascade.
authors.affiliation: Botanisches Institut, Rheinische Friedrich-Wilhelms-Universität Bonn, Department of Plant Cell Biology, Kirschallee 1, D-53115 Bonn, Germany. baluska@uni-bonn.de
authors.forename: F
authors.initials: F
authors.lastname: Baluska
authors.forename: M
authors.initials: M
authors.lastname: von Witsch
authors.forename: M
authors.initials: M
authors.lastname: Peters
authors.forename: A
authors.initials: A
authors.lastname: Hlavacka
authors.forename: D
authors.initials: D
authors.lastname: Volkmann
mesh_terms: D000199:Actins / Q000276:immunology / Q000378:metabolism*; D000911:Antibodies, Monoclonal; D016764:Cell Polarity; D003285:Contractile Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D036341:Intercellular Signaling Peptides and Proteins; D008840:Microfilament Proteins / Q000276:immunology / Q000378:metabolism*; D010455:Peptides; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism; D018518:Plant Root Cap / Q000378:metabolism / Q000648:ultrastructure; D051304:Profilins; D014862:Wasp Venoms / Q000494:pharmacology*; D003313:Zea mays / Q000166:cytology / Q000378:metabolism*
chemical_list: D000199:Actins; D000911:Antibodies, Monoclonal; D003285:Contractile Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008840:Microfilament Proteins; D010455:Peptides; D019269:Phosphatidylinositol 4,5-Diphosphate; D010940:Plant Proteins; D051304:Profilins; D014862:Wasp Venoms; C037500:mastoparan