Transcriptome analysis of the ArgR regulon in Pseudomonas aeruginosa
Transcriptome analysis of the ArgR regulon in Pseudomonas aeruginosa
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DOI：
10.1128/jb.186.12.3855-3861.2004
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发表时间：
2004-06-01
影响因子：
3.2
通讯作者：
Li, W
中科院分区：
文献类型：
--
作者：
Lu, CD;Yang, Z;Li, W
精氨酸在具有多种分解代谢途径的假单胞菌中作为碳和氮源的代谢是研究代谢整合控制的模型系统的特别兴趣。我们进行了转录组分析，以确定精氨酸调节蛋白ArgR控制的基因，并更好地了解P. aeruginosa的精氨酸代谢途径。我们比较了野生型菌株PAO1和在谷氨酸最低培养基中培养的argR突变菌株PAO501在存在和不存在精氨酸条件下的基因表达。在有氧条件下，ArgR和精氨酸可诱导28个基因的10个推定转录单位，包括所有已知的arr调控操纵子。新发现的基因包括adcAB操纵子，它编码一种分解代谢精氨酸脱羧酶和一种反转运蛋白，以及PA0328，它编码一种肽酶和IV型自转运蛋白的融合蛋白。也被确定为精氨酸网络成员的溶质转运系统有：支链氨基酸渗透酶的PA1971 (braZ)；PA2042用于假定的钠：丝氨酸同转运体；PA3934，属于小寡肽转运蛋白家族；以及PA5152-5155，其编码用于假定的视神经摄取系统的ABC转运蛋白的组分。精氨酸对这些基因表达的影响已被lacZ融合研究和纯化ArgR的DNA结合研究证实。9个基因中只有5个转录单位被ArgR和精氨酸抑制，其中3个操纵子（argF、carAB和argG）参与精氨酸生物合成，2个操纵子（gltBD和gdhA）参与谷氨酸生物合成。这些结果表明ArgR在控制精氨酸和谷氨酸代谢中起重要作用，精氨酸和ArgR在诱导某些化合物的摄取系统中可能具有冗余作用。
Arginine metabolism in pseudomonads with multiple catabolic pathways for its utilization as carbon and nitrogen sources is of particular interest as the model system to study control of metabolic integration. We performed transcriptome analyses to identify genes controlled by the arginine regulatory protein ArgR and to better understand arginine metabolic pathways of P. aeruginosa. We compared gene expression in wild-type strain PAO1 with that in argR mutant strain PAO501 grown in glutamate minimal medium in the presence and absence of arginine. Ten putative transcriptional units of 28 genes were inducible by ArgR and arginine, including all known ArgR-regulated operons under aerobic conditions. The newly identified genes include the putative adcAB operon, which encodes a catabolic arginine decarboxylase and an antiporter protein, and PA0328, which encodes a hypothetical fusion protein of a peptidase and a type IV autotransporter. Also identified as members of the arginine network are the following solute transport systems: PA1971 (braZ) for branched-chain amino acids permease; PA2042 for a putative sodium:serine symporter; PA3934, which belongs to the family of small oligopeptide transporters; and PA5152-5155, which encodes components of an ABC transporter for a putative opine uptake system. The effect of arginine on the expression of these genes was confirmed by lacZ fusion studies and by DNA binding studies with purified ArgR. Only five transcriptional units of nine genes were qualified as repressible by ArgR and arginine, with three operons (argF, carAB, and argG) in arginine biosynthesis and two operons (gltBD and gdhA) in glutamate biosynthesis. These results indicate that ArgR is important in control of arginine and glutamate metabolism and that arginine and ArgR may have a redundant effect in inducing the uptake systems of certain compounds.