![]()
|
|
||||||||
J. Biol. Chem., Vol. 275, Issue 23, 17619-17625, June 9, 2000
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From the Istituto Biosintesi Vegetali, Consiglio Nazionale delle
Ricerche, via Bassini 15, 20133 Milano the ¶ Centro Miglioramento
Sanitario Colture Agrarie, Consiglio Nazionale delle Ricerche, via
Celoria 2, Milano 20133 and the Dipartimento di Bologia Strutturale e
Funzionale, Università dell' Insubria, via J. H. Dunant 3,
Varese 21100, Italy
myb7 mRNA is present in rice in
spliced and unspliced forms, splicing being enhanced by anoxia. The
protein (Mybleu) encoded by the unspliced mRNA is composed of an
incomplete Myb domain followed by a leucine zipper; however, it lacks
canonical sequences for DNA binding, transcriptional activation, and
nuclear localization. We show here that in transiently transformed
tobacco protoplasts, Mybleu is able to enhance the transcriptional
activity of the maize leucine zipper Opaque2 on its target
b32 promoter. The Mybleu transactivation effect is strictly
dependent on the presence of Opaque2 and is driven by Mybleu-Opaque2
heterodimers. Mybleu is located in the nucleus, both in rice and in
transformed tobacco protoplasts. In rice, the protein is expressed in
regions corresponding to undifferentiated cells of roots and
coleoptiles. Therefore, myb7 mRNA encodes, depending on
its splicing, two transcription factors belonging to separate classes.
One of them, Mybleu, has novel structural characteristics, suggesting
the existence of new mechanisms acting in the activation of transcription.
The Product of the Rice myb7 Unspliced mRNA
Dimerizes with the Maize Leucine Zipper Opaque2 and Stimulates Its
Activity in a Transient Expression Assay*
,
*
This research was supported in part by the Progetto
Finalizzato Biotecnologie of the Consiglio Nazionale delle Ricerche,
Italy.The costs of publication of this
article were defrayed in part by the
payment of page charges. The article
must therefore be hereby marked
"advertisement" in
accordance with 18 U.S.C. Section
1734 solely to indicate this fact.
Supported by a fellowship from the Consiglio Nazionale delle
Ricerche, Progetto Speciale Biologia e Produzioni Agrarie.
To whom correspondence should be addressed: Istituto
Biosintesi Vegetali, CNR, via Bassini 15, Milano 20133, Italy. Tel.: 39-022-369-9427; Fax: 39-022-369-9411; E-mail:
imma@icm.mi.cnr.it.
This article has been cited by other articles:
![]() |
F. Gavazzi, B. Lazzari, P. Ciceri, E. Gianazza, and A. Viotti Wild-Type Opaque2 and Defective opaque2 Polypeptides Form Complexes in Maize Endosperm Cells and Bind the Opaque2-Zein Target Site Plant Physiology, November 1, 2007; 145(3): 933 - 945. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |