Previous Article | Next Article 
Molecular and Cellular Biology, March 2001, p. 1759-1768, Vol. 21, No. 5
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.5.1759-1768.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
The Balance of Nuclear Import and Export Determines
the Intracellular Distribution and Function of Tomato Heat Stress
Transcription Factor HsfA2
Dirk
Heerklotz,1
Pascal
Döring,1
Frank
Bonzelius,2
Sybille
Winkelhaus,1 and
Lutz
Nover1,*
Department of Molecular Cell
Biology1 and Institute of
Zoology,2 Biocenter, Goethe-University
Frankfurt, Frankfurt am Main, Germany
Received 14 September 2000/Returned for modification 2 November
2000/Accepted 1 December 2000
Tomato heat stress transcription factor HsfA2 is a shuttling
protein with dominant cytoplasmic localization as a result of a nuclear
import combined with an efficient export. Besides the nuclear
localization signal (NLS) adjacent to the oligomerization domain, a
C-terminal leucine-rich motif functions as a nuclear export signal
(NES). Mutant forms of HsfA2 with a defective or an absent NES are
nuclear proteins. The same is true for the wild-type HsfA2 if
coexpressed with HsfA1 or in the presence of export inhibitor leptomycin B (LMB). Fusion of the NES domain of HsfA2 to HsfB1, which
is a nuclear protein, caused export of the HsfB1-A2NES hybrid protein,
and this effect was reversed by the addition of LMB. Due to the lack of
background problems, Chinese hamster ovary (CHO) cells represent an
excellent system for expression and functional analysis of tomato Hsfs.
The results faithfully reflect the situation found in plant cells
(tobacco protoplasts). The intriguing role of NLS and NES accessibility
for the intracellular distribution of HsfA2 is underlined by the
results of heat stress treatments of CHO cells (41°C). Despite the
fact that nuclear import and export are not markedly affected, HsfA2
remains completely cytoplasmic at 41°C even in the presence of LMB.
The temperature-dependent conformational transition of HsfA2 with
shielding of the NLS evidently needs intramolecular interaction between
the internal HR-A/B and the C-terminal HR-C regions. It is not observed
with the HR oligomerization domain (HR-A/B region) deletion form of
HsfA2 or in HsfA2-HsfA1 hetero-oligomers.
*
Corresponding author. Mailing address: Department of
Molecular Cell Biology, Biocenter N200, 30G, Goethe-University
Frankfurt, Marie-Curie-Str. 9, D-60439 Frankfurt, Germany. Phone:
(49)69-798-29284. Fax: (49)69-798-29286. E-mail:
nover{at}cellbiology.uni-frankfurt.de.
Molecular and Cellular Biology, March 2001, p. 1759-1768, Vol. 21, No. 5
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.5.1759-1768.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Giorno, F., Wolters-Arts, M., Grillo, S., Scharf, K.-D., Vriezen, W. H., Mariani, C.
(2009). Developmental and heat stress-regulated expression of HsfA2 and small heat shock proteins in tomato anthers. J Exp Bot
0: erp316v1-erp316
[Abstract]
[Full Text]
-
Chan-Schaminet, K. Y., Baniwal, S. K., Bublak, D., Nover, L., Scharf, K.-D.
(2009). Specific Interaction between Tomato HsfA1 and HsfA2 Creates Hetero-oligomeric Superactivator Complexes for Synergistic Activation of Heat Stress Gene Expression. J. Biol. Chem.
284: 20848-20857
[Abstract]
[Full Text]
-
Cheong, J. K., Gunaratnam, L., Hsu, S. I-H.
(2008). CRM1-mediated Nuclear Export Is Required for 26 S Proteasome-dependent Degradation of the TRIP-Br2 Proto-oncoprotein. J. Biol. Chem.
283: 11661-11676
[Abstract]
[Full Text]
-
Baniwal, S. K., Chan, K. Y., Scharf, K.-D., Nover, L.
(2007). Role of Heat Stress Transcription Factor HsfA5 as Specific Repressor of HsfA4. J. Biol. Chem.
282: 3605-3613
[Abstract]
[Full Text]
-
Tillemans, V., Leponce, I., Rausin, G., Dispa, L., Motte, P.
(2006). Insights into Nuclear Organization in Plants as Revealed by the Dynamic Distribution of Arabidopsis SR Splicing Factors. Plant Cell
18: 3218-3234
[Abstract]
[Full Text]
-
MILLER, G., MITTLER, R.
(2006). Could Heat Shock Transcription Factors Function as Hydrogen Peroxide Sensors in Plants?. ANN BOT (LOND)
98: 279-288
[Abstract]
[Full Text]
-
Port, M., Tripp, J., Zielinski, D., Weber, C., Heerklotz, D., Winkelhaus, S., Bublak, D., Scharf, K.-D.
(2004). Role of Hsp17.4-CII as Coregulator and Cytoplasmic Retention Factor of Tomato Heat Stress Transcription Factor HsfA2. Plant Physiol.
135: 1457-1470
[Abstract]
[Full Text]
-
la Cour, T., Kiemer, L., Molgaard, A., Gupta, R., Skriver, K., Brunak, S.
(2004). Analysis and prediction of leucine-rich nuclear export signals. Protein Eng Des Sel
17: 527-536
[Abstract]
[Full Text]
-
Bharti, K., von Koskull-Doring, P., Bharti, S., Kumar, P., Tintschl-Korbitzer, A., Treuter, E., Nover, L.
(2004). Tomato Heat Stress Transcription Factor HsfB1 Represents a Novel Type of General Transcription Coactivator with a Histone-Like Motif Interacting with the Plant CREB Binding Protein Ortholog HAC1. Plant Cell
16: 1521-1535
[Abstract]
[Full Text]
-
Hare, P. D., Moller, S. G., Huang, L.-F., Chua, N.-H.
(2003). LAF3, a Novel Factor Required for Normal Phytochrome A Signaling. Plant Physiol.
133: 1592-1604
[Abstract]
[Full Text]
-
Olson, V. A., Wetter, J. A., Friesen, P. D.
(2002). Baculovirus Transregulator IE1 Requires a Dimeric Nuclear Localization Element for Nuclear Import and Promoter Activation. J. Virol.
76: 9505-9515
[Abstract]
[Full Text]
-
Rojas, A., Almoguera, C., Carranco, R., Scharf, K.-D., Jordano, J.
(2002). Selective Activation of the Developmentally Regulated Ha hsp17.6 G1 Promoter by Heat Stress Transcription Factors. Plant Physiol.
129: 1207-1215
[Abstract]
[Full Text]
-
Mishra, S. K., Tripp, J., Winkelhaus, S., Tschiersch, B., Theres, K., Nover, L., Scharf, K.-D.
(2002). In the complex family of heat stress transcription factors, HsfA1 has a unique role as master regulator of thermotolerance in tomato. Genes Dev.
16: 1555-1567
[Abstract]
[Full Text]
-
Zeidler, M., Bolle, C., Chua, N.-H.
(2001). The Phytochrome A Specific Signaling Component PAT3 is a Positive Regulator of Arabidopsis Photomorphogenesis. Plant Cell Physiol
42: 1193-1200
[Abstract]
[Full Text]