title: Altered expression of an ankyrin-repeat protein results in leaf abnormalities, necrotic lesions, and the elaboration of a systemic signal.
abstract: The PR-like proteins, class I beta-1,3-glucanase (GLU I) and chitinase (CHN I), are induced as part of a stereotypic response that can provide protection against viral, bacterial, and fungal pathogens. We have identified two Nicotiana plumbaginifolia ankyrin-repeat proteins, designated Glucanohydrolase Binding Proteins (GBP) 1 and 2, that bind GLU I and CHN I both in vitro and when expressed in yeast cells. Sense as well as antisense transformants of tobacco carrying the GBP1 gene elaborated graft-transmissible acropetally moving signals that induced the downward curling of young leaves. This phenotype was associated with reduced starch, sucrose, and fructose accumulation; the formation of necrotic lesions; and, the induction of markers for the hypersensitive response. GBP1/2 are members of a conserved Plant- Specific Ankyrin- repeat (PANK) family that includes proteins implicated in carbohydrate allocation, reactive oxygen metabolism, hypersensitive cell death, rapid elicitor responses, virus pathogenesis, and auxin signaling. The similarity in phenotype of PANK transformants and transformants altered in carbohydrate metabolism leads us to propose that PANK family members are multifunctional proteins involved in linking plant defense responses and carbohydrate metabolism.
authors.affiliation: The Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.
authors.forename: Corina
authors.initials: C
authors.lastname: Wirdnam
authors.forename: Andrea
authors.initials: A
authors.lastname: Motoyama
authors.forename: Estelle
authors.initials: E
authors.lastname: Arn-Bouldoires
authors.forename: Sjoerd
authors.initials: S
authors.lastname: van Eeden
authors.forename: Alejandro
authors.initials: A
authors.lastname: Iglesias
authors.forename: Frederick
authors.initials: F
authors.lastname: Meins
mesh_terms: D017089:Ankyrin Repeat / Q000235:genetics*; D050260:Carbohydrate Metabolism; D002688:Chitinases / Q000235:genetics / Q000378:metabolism; D043326:Glucan 1,3-beta-Glucosidase / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D008954:Models, Biological; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics* / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D015003:Yeasts / Q000235:genetics
chemical_list: D010940:Plant Proteins; D020033:Protein Isoforms; D002688:Chitinases; D043326:Glucan 1,3-beta-Glucosidase