title: Stress induced and nuclear localized HIPP26 from Arabidopsis thaliana interacts via its heavy metal associated domain with the drought stress related zinc finger transcription factor ATHB29.
abstract: HIPP26 from Arabidopsis thaliana belongs to a novel class of plant proteins, characterized by a heavy metal associated domain and an additional isoprenylation motif. It is induced during cold, salt and drought stress. The nuclear localization of HIPP26, predicted by a NLS motif, could be confirmed in onion epidermal cells overexpressing GFP-HIPP26. Experiments with modified HIPP26 indicate that the isoprenylation plays a role in the spatial distribution in the nucleus. Using promoter-GUS constructs, a tissue specific expression pattern of HIPP26 could be shown, with high expression in the vascular tissue. By a yeast-two-hybrid approach a strong interaction of HIPP26 with the zinc finger homeodomain transcription factor ATHB29, which is known to play a role in dehydration stress response could be detected. This was confirmed by GST pull-down assays. When using a modified HIPP26 lacking the two central cysteines of the heavy metal associated domain, ATHB29 was not bound in the GST pull-down assay, indicating that this structure is necessary for the interaction. Further yeast-two-hybrid analyses testing interaction of different members of the HIPP family with related zinc finger transcription factors revealed a specific interaction of ATHB29 with several HIPP proteins. A functional relationship between HIPP26 and ATHB29 is also indicated by experiments with mutants of HIPP26 showing altered expression levels of such genes known to be regulated by ATHB29.
authors.affiliation: Institute of Biology, Martin-Luther-University Halle-Wittenberg, Weinbergweg 10, 06120 Halle, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Barth
authors.forename: Sebastian
authors.initials: S
authors.lastname: Vogt
authors.forename: Ria
authors.initials: R
authors.lastname: Uhlemann
authors.forename: Wiebke
authors.initials: W
authors.lastname: Zschiesche
authors.forename: Klaus
authors.initials: K
authors.lastname: Humbeck
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D055864:Droughts; D019216:Metals, Heavy / Q000378:metabolism*; D010802:Phylogeny; D011485:Protein Binding; D017368:Protein Prenylation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D016335:Zinc Fingers
chemical_list: D029681:Arabidopsis Proteins; D019216:Metals, Heavy; D014157:Transcription Factors