Plant Transcription Factor Database
Previous version: v3.0
Arabidopsis thaliana
HSF Family
Species TF ID Description
AT1G32330.1heat shock transcription factor A1D
AT1G46264.1heat shock transcription factor B4
AT1G67970.1heat shock transcription factor A8
AT1G77570.1Winged helix-turn-helix transcription repressor DNA-binding
AT2G26150.1heat shock transcription factor A2
AT2G41690.1heat shock transcription factor B3
AT3G02990.1heat shock transcription factor A1E
AT3G22830.1heat shock transcription factor A6B
AT3G24520.1heat shock transcription factor C1
AT3G51910.1heat shock transcription factor A7A
AT3G63350.1HSF family protein
AT4G11660.1HSF family protein
AT4G13980.1HSF family protein
AT4G17750.1heat shock factor 1
AT4G18870.1HSF family protein
AT4G18880.1heat shock transcription factor A4A
AT4G19630.1HSF family protein
AT4G36990.1heat shock factor 4
AT5G03720.1heat shock transcription factor A3
AT5G16820.1heat shock factor 3
AT5G16820.2heat shock factor 3
AT5G43840.1heat shock transcription factor A6A
AT5G45710.1HSF family protein
AT5G54070.1heat shock transcription factor A9
AT5G62020.1heat shock transcription factor B2A
HSF Family Introduction

Heat stress transcription factors (Hsfs) are the major regulators of the plant heat stress (hs) response. Sequencing of the Arabidopsis genome revealed the existence of 21 open-reading frames (ORFs) encoding putative Hsfs assigned to classes A-C. Here we present results of a functional genomics approach to the Arabidopsis Hsf family focused on the analysis of their C-terminal domains (CTDs) harboring conserved modules for their function as transcription factors and their intracellular localization. Using reporter assays in tobacco protoplasts and yeast as well as glutathione-S-transferase (GST) pull-down assays, we demonstrate that short peptide motifs enriched with aromatic and large hydrophobic amino acid (aa) residues embedded in an acidic surrounding (AHA motifs) are essential for transcriptional activity of class A Hsfs. In contrast to this, class B and C Hsfs lack AHA motifs and have no activator function on their own. We also provide evidence for the function of a leucine (Leu)-rich region centered around a conserved QMGΦL motif at the very C-terminus as a nuclear export signal (NES) of class A Hsfs. Sequence comparison indicates that the combination of a C-terminal AHA motif with the consensus sequence FWxxF/L,F/I/L as well as the adjacent NES represents a signature domain for plant class A Hsfs, which allowed to identify more than 60 new Hsfs from the expressed sequence tag (EST) database.

Kotak S, Port M, Ganguli A, Bicker F, von Koskull-Doring P.
Characterization of C-terminal domains of Arabidopsis heat stress transcription factors (Hsfs) and identification of a new signature combination of plant class A Hsfs with AHA and NES motifs essential for activator function and intracellular localization.
Plant J, 2004. 39(1): p. 98-112.
PMID: 15200645