This Article Full Text Full Text (PDF) All Versions of this Article: 135/3/1457    most recent pp.104.042820v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (21) Citing Articles via Google Scholar Google Scholar Articles by Port, M. Articles by Scharf, K.-D. Search for Related Content PubMed PubMed Citation Articles by Port, M. Articles by Scharf, K.-D. Pubmed/NCBI databases Gene GEO Profiles HomoloGene Protein UniGene Agricola Articles by Port, M. Articles by Scharf, K.-D.

CELL BIOLOGY AND SIGNAL TRANSDUCTION

Role of Hsp17.4-CII as Coregulator and Cytoplasmic Retention Factor of Tomato Heat Stress Transcription Factor HsfA2¹

Biocenter of the Goethe University, D–60439 Frankfurt am Main, Germany

HsfA2 is a heat stress (hs)-induced Hsf in peruvian tomato (Lycopersicon peruvianum) and the cultivated form Lycopersicon esculentum. Due to the high activator potential and the continued accumulation during repeated cycles of heat stress and recovery, HsfA2 becomes a dominant Hsf in thermotolerant cells. The formation of heterooligomeric complexes with HsfA1 leads to nuclear retention and enhanced transcriptional activity of HsfA2. This effect seems to represent one part of potential molecular mechanisms involved in its activity control. As shown in this paper, the activity of HsfA2 is also controlled by a network of nucleocytoplasmic small Hsps influencing its solubility, intracellular localization and activator function. By yeast two-hybrid interaction and transient coexpression studies in tobacco (Nicotiana plumbaginifolia) mesophyll protoplasts, we found that tomato (Lycopersicon esculentum) Hsp17.4-CII acts as corepressor of HsfA2. Given appropriate conditions, both proteins together formed large cytosolic aggregates which could be solubilized in presence of class CI sHsps. However, independent of the formation of aggregates or of the nucleocytoplasmic distribution of HsfA2, its transcriptional activity was specifically repressed by interaction of Hsp17.4-CII with the C-terminal activator domain. Although not identical in all aspects, the situation with the highly expressed, heat stress-inducible Arabidopsis HsfA2 was found to be principally similar. In corresponding reporter assays its activity was repressed in presence of AtHsp17.7-CII but not of AtHsp17.6-CII or LpHsp17.4-CII.

Article, publication date, and citation information can be found at www.plantphysiol.org/cgi/doi/10.1104/pp.104.042820.

^* Corresponding author; e-mail scharf{at}cellbiology.uni-frankfurt.de; fax 49–69–798–29286.

Received March 16, 2004; returned for revision May 16, 2004; accepted May 16, 2004.

This article has been cited by other articles:

				F. Giorno, M. Wolters-Arts, S. Grillo, K.-D. Scharf, W. H. Vriezen, and C. Mariani Developmental and heat stress-regulated expression of HsfA2 and small heat shock proteins in tomato anthers J. Exp. Bot., October 23, 2009; (2009) erp316v1. [Abstract] [Full Text] [PDF]

				K. Y. Chan-Schaminet, S. K. Baniwal, D. Bublak, L. Nover, and K.-D. Scharf Specific Interaction between Tomato HsfA1 and HsfA2 Creates Hetero-oligomeric Superactivator Complexes for Synergistic Activation of Heat Stress Gene Expression J. Biol. Chem., July 31, 2009; 284(31): 20848 - 20857. [Abstract] [Full Text] [PDF]

				H. Gao, F. Brandizzi, C. Benning, and R. M. Larkin A membrane-tethered transcription factor defines a branch of the heat stress response in Arabidopsis thaliana PNAS, October 21, 2008; 105(42): 16398 - 16403. [Abstract] [Full Text] [PDF]

				K. Yamada, Y. Fukao, M. Hayashi, M. Fukazawa, I. Suzuki, and M. Nishimura Cytosolic HSP90 Regulates the Heat Shock Response That Is Responsible for Heat Acclimation in Arabidopsis thaliana J. Biol. Chem., December 28, 2007; 282(52): 37794 - 37804. [Abstract] [Full Text] [PDF]

				S. K. Baniwal, K. Y. Chan, K.-D. Scharf, and L. Nover Role of Heat Stress Transcription Factor HsfA5 as Specific Repressor of HsfA4 J. Biol. Chem., February 9, 2007; 282(6): 3605 - 3613. [Abstract] [Full Text] [PDF]

				Y.-y. Charng, H.-c. Liu, N.-y. Liu, W.-t. Chi, C.-n. Wang, S.-h. Chang, and T.-t. Wang A Heat-Inducible Transcription Factor, HsfA2, Is Required for Extension of Acquired Thermotolerance in Arabidopsis Plant Physiology, January 1, 2007; 143(1): 251 - 262. [Abstract] [Full Text] [PDF]

				S. FERREIRA, K. HJERNO, M. LARSEN, G. WINGSLE, P. LARSEN, S. FEY, P. ROEPSTORFF, and M. SALOME PAIS Proteome Profiling of Populus euphratica Oliv. Upon Heat Stress Ann. Bot., August 1, 2006; 98(2): 361 - 377. [Abstract] [Full Text] [PDF]

				G. MILLER and R. MITTLER Could Heat Shock Transcription Factors Function as Hydrogen Peroxide Sensors in Plants? Ann. Bot., August 1, 2006; 98(2): 279 - 288. [Abstract] [Full Text] [PDF]

				T. Hayakawa, T. Kudo, T. Ito, N. Takahashi, and T. Yamaya ACT Domain Repeat Protein 7, ACR7, Interacts with a Chaperone HSP18.0-CII in Rice Nuclei Plant Cell Physiol., July 1, 2006; 47(7): 891 - 904. [Abstract] [Full Text] [PDF]

				S. Vanderauwera, P. Zimmermann, S. Rombauts, S. Vandenabeele, C. Langebartels, W. Gruissem, D. Inze, and F. Van Breusegem Genome-Wide Analysis of Hydrogen Peroxide-Regulated Gene Expression in Arabidopsis Reveals a High Light-Induced Transcriptional Cluster Involved in Anthocyanin Biosynthesis Plant Physiology, October 1, 2005; 139(2): 806 - 821. [Abstract] [Full Text] [PDF]