title: Rab geranylgeranyl transferase β subunit is essential for male fertility and tip growth in Arabidopsis.
abstract: Rab proteins, key players in vesicular transport in all eukaryotic cells, are post-translationally modified by lipid moieties. Two geranylgeranyl groups are attached to the Rab protein by the heterodimeric enzyme Rab geranylgeranyl transferase (RGT) αβ. Partial impairment in this enzyme activity in Arabidopsis, by disruption of the AtRGTB1 gene, is known to influence plant stature and disturb gravitropic and light responses. Here it is shown that mutations in each of the RGTB genes cause a tip growth defect, visible as root hair and pollen tube deformations. Moreover, FM 1-43 styryl dye endocytosis and recycling are affected in the mutant root hairs. Finally, it is demonstrated that the double mutant, with both AtRGTB genes disrupted, is non-viable due to absolute male sterility. Doubly mutated pollen is shrunken, has an abnormal exine structure, and shows strong disorganization of internal membranes, particularly of the endoplasmic reticulum system.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland gosiag@ibb.waw.pl.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Gutkowska
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Wnuk
authors.affiliation: Warsaw University, Faculty of Biology, Miecznikowa 1, 02-096 Warsaw, Poland.
authors.forename: Julita
authors.initials: J
authors.lastname: Nowakowska
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Lichocka
authors.affiliation: Warsaw University of Technology, Faculty of Mathematics and Information Science, Koszykowa 75, 00-662 Warsaw, Poland.
authors.forename: Michal M
authors.initials: MM
authors.lastname: Stronkowski
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Swiezewska
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D005298:Fertility / Q000235:genetics; D035264:Flowers / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D008969:Molecular Sequence Data; D009154:Mutation; D011058:Pollen / Q000378:metabolism; D053205:Pollen Tube / Q000254:growth & development; D012098:Reproduction; D014166:Transferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C095279:Rab geranylgeranyl transferase beta-subunit; D014166:Transferases; D019883:Alkyl and Aryl Transferases; C075607:Rab geranylgeranyltransferase
keywords: Arabidopsis; Rab geranylgeranyl transferase; Rab protein; male fertility; pollen; pollen tube; protein prenylation; root hair; tip growth.