Contrasting activities of the aggregative and late PDSA promoters in Dictyostelium development.
Contrasting activities of the aggregative and late PDSA promoters in Dictyostelium development.
复制标题
盘基网柄菌发育中聚集和晚期 PDSA 启动子的活性对比。
DOI：
10.1016/s0012-1606(02)00077-5
复制
发表时间：
2003
影响因子：
2.7
通讯作者：
Schaap,Pauline
中科院分区：
文献类型：
--
作者：
Weening,KarinE;Wijk,IreneVerkerke-Van;Thompson,ChristopherR;Kessin,RichardH;Podgorski,GregoryJ;Schaap,Pauline
从聚集（PdA）和晚期（PdL）启动子表达网囊藻PdsA基因分别对于聚集和蛞蝓形态发生是必需的。我们使用不稳定的β-半乳糖苷酶（gal）报告酶研究了蛞蝓中PdA和PdL启动子的调控。PdL在前柄细胞中是活跃的，也发现稳定的半乳糖。PdA活性下降强烈蛞蝓从所有的细胞，除了那些在后方。这几乎与用稳定的半乳糖追踪的PdA活性相反，其中蛞蝓显示出持续的活性，在前部具有最高水平。PdA下调后，无论与已知的控制基因表达的任何因素的刺激聚集。cAMP和DIF协同作用诱导细胞悬液中的PdL活性。然而，DIF-少的突变体在发育过程中显示正常的PdL活性，表明DIF在体内不控制PdL。对PdL启动子的解剖表明，所有对启动子活性的正确时空控制至关重要的序列都位于转录起始位点的下游，相对于起始密码子，位于-383到-19个核苷酸之间。去除-364位的核苷酸消除了对DIF和cAMP的反应性，但蛞蝓前柄细胞中的正常PdL活性得以保留。进一步的5′端缺失消除了所有的启动子活性。该结果还表明，在细胞悬浮液中所见的DIF和cAMP的诱导对于正常发育中的PdL活性不是必需的。
Expression of the Dictyostelium PdsA gene from the aggregative (PdA) and late (PdL) promoter is essential for aggregation and slug morphogenesis, respectively. We studied the regulation of the PdA and PdL promoters in slugs using labile β-galactosidase (gal) reporter enzymes. PdL was active in prestalk cells as was also found with stable gal. PdA activity decreased strongly in slugs from all cells, except those at the rear. This is almost opposite to PdA activity traced with stable gal, where slugs showed sustained activity with highest levels at the front. PdA was down-regulated after aggregation irrespective of stimulation with any of the factors known to control gene expression. PdL activity was induced in cell suspension by cAMP and DIF acting in synergy. However, a DIF-less mutant showed normal PdL activity during development, suggesting that DIF does not control PdL in vivo. Dissection of the PdL promoter showed that all sequences essential for correct spatiotemporal control of promoter activity are downstream of the transcription start site in a region between −383 and −19 nucleotides relative to the start codon. Removal of nucleotides to position −364 eliminated responsiveness to DIF and cAMP, but normal PdL activity in prestalk cells in slugs was retained. Further 5′ deletions abolished all promoter activity. This result also indicates that the induction by DIF and cAMP as seen in cell suspensions is not essential for PdL activity in normal development.