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Title: Identification of cis-acting elements important for expression of the starch-branching enzyme I gene in maize endosperm

Abstract

The genes encoding the starch-branching enzymes (SBE) SBEI, SBEIIa, and SBEIIb in maize (Zea mays) are differentially regulated in tissue specificity and during kernel development. To gain insight into the regulatory mechanisms controlling their expression, the authors analyzed the 5{prime}=flanking sequences of SbeI using a transient gene expression system. Although the 2.2-kb 5{prime}-flanking sequence between {minus}2,190 and +27 relative to the transcription initiation site was sufficient to promote transcription, the addition of the transcribed region between +28 and +228 containing the first exon and intron resulted in high-level expression in suspension-cultured maize endosperm cells. A series of 5{prime} deletion and linker-substitution mutants identified two critical positive cis elements, {minus}314 to {minus}295 and {minus}284 to {minus}255. An electrophoretic mobility-shift assay showed that nuclear proteins prepared from maize kernels interact with the 60-bp fragment containing these two elements. Expression of the SbeI gene is regulated by sugar concentration in suspension-cultured maize endosperm cells, and the region {minus}314 to {minus}145 is essential for this effect. Interestingly, the expression of mEmBP-I,k a bZIP transcription activator, in suspension-cultured maize endosperm cells resulted in a 5-fold decrease in SbeI promoter activity, suggesting a possible regulatory role of the G-box present in the SbeI promoter from {minus}227more » to {minus}220.« less

Authors:
;
Publication Date:
Research Org.:
Pennsylvania State Univ., University Park, PA (US)
Sponsoring Org.:
USDOE
OSTI Identifier:
20006206
DOE Contract Number:  
FG02-96ER20234
Resource Type:
Journal Article
Journal Name:
Plant Physiology (Bethesda)
Additional Journal Information:
Journal Volume: 121; Journal Issue: 1; Other Information: PBD: Sep 1999; Journal ID: ISSN 0032-0889
Country of Publication:
United States
Language:
English
Subject:
55 BIOLOGY AND MEDICINE, BASIC STUDIES; MAIZE; GENE REGULATION; TRANSCRIPTION; ENDOSPERM; STARCH; ENZYMES; BIOLOGICAL PATHWAYS

Citation Formats

Kim, K.N., and Guiltinan, M.J. Identification of cis-acting elements important for expression of the starch-branching enzyme I gene in maize endosperm. United States: N. p., 1999. Web. doi:10.1104/pp.121.1.225.
Kim, K.N., & Guiltinan, M.J. Identification of cis-acting elements important for expression of the starch-branching enzyme I gene in maize endosperm. United States. doi:10.1104/pp.121.1.225.
Kim, K.N., and Guiltinan, M.J. Wed . "Identification of cis-acting elements important for expression of the starch-branching enzyme I gene in maize endosperm". United States. doi:10.1104/pp.121.1.225.
@article{osti_20006206,
title = {Identification of cis-acting elements important for expression of the starch-branching enzyme I gene in maize endosperm},
author = {Kim, K.N. and Guiltinan, M.J.},
abstractNote = {The genes encoding the starch-branching enzymes (SBE) SBEI, SBEIIa, and SBEIIb in maize (Zea mays) are differentially regulated in tissue specificity and during kernel development. To gain insight into the regulatory mechanisms controlling their expression, the authors analyzed the 5{prime}=flanking sequences of SbeI using a transient gene expression system. Although the 2.2-kb 5{prime}-flanking sequence between {minus}2,190 and +27 relative to the transcription initiation site was sufficient to promote transcription, the addition of the transcribed region between +28 and +228 containing the first exon and intron resulted in high-level expression in suspension-cultured maize endosperm cells. A series of 5{prime} deletion and linker-substitution mutants identified two critical positive cis elements, {minus}314 to {minus}295 and {minus}284 to {minus}255. An electrophoretic mobility-shift assay showed that nuclear proteins prepared from maize kernels interact with the 60-bp fragment containing these two elements. Expression of the SbeI gene is regulated by sugar concentration in suspension-cultured maize endosperm cells, and the region {minus}314 to {minus}145 is essential for this effect. Interestingly, the expression of mEmBP-I,k a bZIP transcription activator, in suspension-cultured maize endosperm cells resulted in a 5-fold decrease in SbeI promoter activity, suggesting a possible regulatory role of the G-box present in the SbeI promoter from {minus}227 to {minus}220.},
doi = {10.1104/pp.121.1.225},
journal = {Plant Physiology (Bethesda)},
issn = {0032-0889},
number = 1,
volume = 121,
place = {United States},
year = {1999},
month = {9}
}