title: Characterization of pollen-expressed bZIP protein interactions and the role of ATbZIP18 in the male gametophyte.
abstract: KEY MESSAGE : bZIP TF network in pollen. Transcriptional control of gene expression represents an important mechanism guiding organisms through developmental processes and providing plasticity towards environmental stimuli. Because of their sessile nature, plants require effective gene regulation for rapid response to variation in environmental and developmental conditions. Transcription factors (TFs) provide such control ensuring correct gene expression in spatial and temporal manner. Our work reports the interaction network of six bZIP TFs expressed in Arabidopsis thaliana pollen and highlights the potential functional role for AtbZIP18 in pollen. AtbZIP18 was shown to interact with three other pollen-expressed bZIP TFs-AtbZIP34, AtbZIP52, and AtbZIP61 in yeast two-hybrid assays. AtbZIP18 transcripts are highly expressed in pollen, and at the subcellular level, an AtbZIP18-GFP fusion protein was located in the nucleus and cytoplasm/ER. To address the role of AtbZIP18 in the male gametophyte, we performed phenotypic analysis of a T-DNA knockout allele, which showed slightly reduced transmission through the male gametophyte. Some of the phenotype defects in atbzip18 pollen, although observed at low penetrance, were similar to those seen at higher frequency in the T-DNA knockout of the interacting partner, AtbZIP34. To gain deeper insight into the regulatory role of AtbZIP18, we analysed atbzip18/- pollen microarray data. Our results point towards a potential repressive role for AtbZIP18 and its functional redundancy with AtbZIP34 in pollen.
authors.affiliation: Laboratory of Pollen Biology, Institute of Experimental Botany AS CR, v. v. i., Rozvojová 263, 165 02, Prague 6, Czech Republic.
authors.forename: Antónia
authors.initials: A
authors.lastname: Gibalová
authors.affiliation: Laboratory of Pollen Biology, Institute of Experimental Botany AS CR, v. v. i., Rozvojová 263, 165 02, Prague 6, Czech Republic.
authors.forename: Lenka
authors.initials: L
authors.lastname: Steinbachová
authors.affiliation: Laboratory of Pollen Biology, Institute of Experimental Botany AS CR, v. v. i., Rozvojová 263, 165 02, Prague 6, Czech Republic.
authors.forename: Said
authors.initials: S
authors.lastname: Hafidh
authors.affiliation: Laboratory of Pollen Biology, Institute of Experimental Botany AS CR, v. v. i., Rozvojová 263, 165 02, Prague 6, Czech Republic.|Department of Physiology, Faculty of Science, Charles University in Prague, Viničná 7, 128 44, Prague 2, Czech Republic.|Institute of Physiology AS CR, v. v. i., Vídeňská 1083, 142 20, Prague 4, Czech Republic.|National Institute of Mental Health, Topolová 748, 250 67, Klecany, Czech Republic.
authors.forename: Veronika
authors.initials: V
authors.lastname: Bláhová
authors.affiliation: Laboratory of Pollen Biology, Institute of Experimental Botany AS CR, v. v. i., Rozvojová 263, 165 02, Prague 6, Czech Republic.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Gadiou
authors.affiliation: Laboratory of Pollen Biology, Institute of Experimental Botany AS CR, v. v. i., Rozvojová 263, 165 02, Prague 6, Czech Republic.
authors.forename: Christos
authors.initials: C
authors.lastname: Michailidis
authors.affiliation: Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany AS CR, v. v. i., Rozvojová 263, 165 02, Prague 6, Czech Republic.
authors.forename: Karel
authors.initials: K
authors.lastname: Műller
authors.affiliation: Laboratory of Cell Biology, Institute of Experimental Botany AS CR, v. v. i., Rozvojová 263, 165 02, Prague 6, Czech Republic.|Laboratory of Pavel Jungwirth, Institute of Organic Chemistry and Biochemistry AS CR, v. v. i., Flemingovo nám. 2, 166 10, Prague 6, Czech Republic.
authors.forename: Roman
authors.initials: R
authors.lastname: Pleskot
authors.affiliation: Laboratory of Pollen Biology, Institute of Experimental Botany AS CR, v. v. i., Rozvojová 263, 165 02, Prague 6, Czech Republic.
authors.forename: Nikoleta
authors.initials: N
authors.lastname: Dupľáková
authors.affiliation: Laboratory of Pollen Biology, Institute of Experimental Botany AS CR, v. v. i., Rozvojová 263, 165 02, Prague 6, Czech Republic. david@ueb.cas.cz.
authors.forename: David
authors.initials: D
authors.lastname: Honys
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000378:metabolism*; D018744:DNA, Plant; D019281:Dimerization; D018506:Gene Expression Regulation, Plant; D016254:Mutagenesis, Insertional; D011058:Pollen / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D018744:DNA, Plant; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; C000621058:bZIP18 protein, Arabidopsis; C542093:bZIP34 protein, Arabidopsis
keywords: Male gametophyte; Pollen development; Regulatory network; Transcription factors; Y2H; bZIP