Transcriptional control of aspartate kinase expression during darkness and sugar depletion in Arabidopsis: involvement of bZIP transcription factors
Transcriptional control of aspartate kinase expression during darkness and sugar depletion in Arabidopsis: involvement of bZIP transcription factors
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拟南芥黑暗和糖消耗期间天冬氨酸激酶表达的转录控制：bZIP转录因子的参与
DOI：
10.1007/s00425-011-1360-9
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发表时间：
2010
期刊：
影响因子：
4.3
通讯作者：
Zilberstein
中科院分区：
文献类型：
--
作者：
Shukla;Soloveichik;Breuer;Galili;Zilberstein
Initial steps of aspartate-derived biosynthesis pathway (Asp pathway) producing Lys, Thr, Met and Ile are catalyzed by bifunctional (AK/HSD) and monofunctional (AK-lys) aspartate kinase (AK) enzymes. Here, we show that transcription of allAKgenes is negatively regulated under darkness and low sugar conditions. By using yeast one-hybrid assays and complementary chromatin immunoprecipitation analyses inArabidopsiscells, the bZIP transcription factors ABI5 and DPBF4 were identified, capable of interacting with the G-box-containing enhancer ofAK/HSD1promoter. Elevated transcript levels ofDPBF4andABI5under darkness and low sugar conditions coincide with the repression ofAKgene expression. Overexpression of ABI5, but not DPBF4, further increases thisAKtranscription suppression. Concomitantly, it also increases the expression of asparagines synthetase 1 (ASN1) that shifts aspartate utilization towards asparagine formation. However, inabi5ordpbf4mutant andabi5,dpbf4double mutant the repression ofAKexpression is maintained, indicating a functional redundancy with other bZIP-TFs. A dominant-negative version of DPBF4 fused to the SRDX repressor domain of SUPERMAN could counteract the repression and stimulateAKexpression under low sugar and darkness in planta. This effect was verified by showing that DPBF4-SRDX fails to recognize theAK/HSD1enhancer sequence in yeast one-hybrid assays, but increases heterodimmer formation with DPBF4 and ABI5, as estimated by yeast two-hybrid assays. Hence it is likely that heterodimerization with DPBF4-SRDX inhibits the binding of redundantly functioning bZIP-TFs to the promoters ofAKgenes and thereby releases the repressing effect. These data highlight a novel transcription control of the chloroplast aspartate pathway that operates under energy limiting conditions.
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影响因子：
7.2
作者：
Ferrando, A;Farràs, R;Koncz, C
通讯作者：
Koncz, C
影响因子：
7.2
作者：
Lopez-Molina, L;Mongrand, B;Chua, NH
通讯作者：
Chua, NH
影响因子：
--
作者：
Mendrysa SM;Akagi K;Roayaei J;Lien WH;Copeland NG;Jenkins NA;Eisenman RN
通讯作者：
Eisenman RN
编码与大肠杆菌赖氨酸敏感酶同源的单功能天冬氨酸激酶的拟南芥 cDNA 的克隆和表达
影响因子：
5.1
作者：
G. Tang;J. Zhu;R. Amir;Inbal Ben;G. Galili
通讯作者：
G. Galili
拟南芥单功能天冬氨酸激酶基因的空间和时间调控表达的鉴定。
影响因子：
1.1
作者：
Y. Yoshioka;S. Kurei;Y. Machida
通讯作者：
Y. Machida