Axenic Leishmania amazonensis promastigotes sense both the external and internal arginine pool distinctly regulating the two transporter-coding genes.
Axenic Leishmania amazonensis promastigotes sense both the external and internal arginine pool distinctly regulating the two transporter-coding genes.
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DOI：
10.1371/journal.pone.0027818
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Floeter-Winter LM
中科院分区：
文献类型：
--
作者：
Castilho-Martins EA;Laranjeira da Silva MF;dos Santos MG;Muxel SM;Floeter-Winter LM
利什曼原虫（L.）亚马逊河使用精氨酸来合成多胺以支持其生长和存活。在这里，我们描述了存在两个基因拷贝，串联排列，编码精氨酸转运蛋白。两个拷贝显示相似的开放阅读框架（ORF），其与L.（L.）donovani AAP 3基因的5′和3′非翻译区有明显的差异。根据定量RT-PCR，沿着前鞭毛体生长曲线，5.1 AAP 3 mRNA的量增加了4.7 AAP 3 mRNA的3倍多。营养剥夺4小时，然后补充或不补充精氨酸（400 µM），与饥饿和对照寄生虫相比，产生了相似的4.7 AAP 3 mRNA拷贝数。相反，5.1 AAP 3 mRNA拷贝数在饥饿的寄生虫中增加，但在补充精氨酸的寄生虫中没有增加（p<0.05）。这些结果与氨基酸摄取的增加相关。Meta 1和β-淀粉酶mRNA在补充或不补充的情况下保持恒定。用L.（L.）amazonensis空敲除突变体（arg -）和另外两个突变体（arg-/argΔSKL）。arg -和arg -/argΔSKL突变体没有表现出与野生型（WT）寄生虫或arg -/ARG突变体相同的行为。这可能表明精氨酸的内部库对于控制转运蛋白的表达和功能也很重要。通过抑制mRNA转录或/和mRNA成熟，我们发现5.1 AAP 3 mRNA在180 min后没有衰减，但4.7 AAP 3 mRNA的半衰期衰减为32.6 +/-5.0 min。总之，寄生虫可以通过增加转运蛋白编码mRNA的量来调节氨基酸摄取，可能是通过在氨基酸不存在或含量低的环境中调节mRNA半衰期。
Leishmania (L.) amazonensis uses arginine to synthesize polyamines to support its growth and survival. Here we describe the presence of two gene copies, arranged in tandem, that code for the arginine transporter. Both copies show similar Open Reading Frames (ORFs), which are 93% similar to the L. (L.) donovani AAP3 gene, but their 5′ and 3′ UTR's have distinct regions. According to quantitative RT-PCR, the 5.1 AAP3 mRNA amount was increased more than 3 times that of the 4.7 AAP3 mRNA along the promastigote growth curve. Nutrient deprivation for 4 hours and then supplemented or not with arginine (400 µM) resulted in similar 4.7 AAP3 mRNA copy-numbers compared to the starved and control parasites. Conversely, the 5.1 AAP3 mRNA copy-numbers increased in the starved parasites but not in ones supplemented with arginine (p<0.05). These results correlate with increases in amino acid uptake. Both Meta1 and arginase mRNAs remained constant with or without supplementation. The same starvation experiment was performed using a L. (L.) amazonensis null knockout for arginase (arg -) and two other mutants containing the arginase ORF with (arg -/ARG) or without the glycosomal addressing signal (arg -/argΔSKL). The arg - and the arg -/argΔSKL mutants did not show the same behavior as the wild-type (WT) parasite or the arg -/ARG mutant. This can be an indicative that the internal pool of arginine is also important for controlling transporter expression and function. By inhibiting mRNA transcription or/and mRNA maturation, we showed that the 5.1 AAP3 mRNA did not decay after 180 min, but the 4.7 AAP3 mRNA presented a half-life decay of 32.6 +/− 5.0 min. In conclusion, parasites can regulate amino acid uptake by increasing the amount of transporter-coding mRNA, possibly by regulating the mRNA half-life in an environment where the amino acid is not present or is in low amounts.
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影响因子：
2.1
作者：
CAMARGO, EP;COELHO, JA;FIGUEIREDO, EN
通讯作者：
FIGUEIREDO, EN
DOI：
10.4269/ajtmh.1996.54.486
发表时间：
1996-05-01
影响因子：
3.3
作者：
Evans, TG;Reed, SS;Hibbs, JB
通讯作者：
Hibbs, JB
DOI：
10.1016/j.bbrc.2003.07.020
发表时间：
2004-01-09
影响因子：
3.1
作者：
Jousse, C;Averous, J;Fafournoux, P
通讯作者：
Fafournoux, P
DOI：
10.1016/j.bbrc.2004.09.212
发表时间：
2004-12-03
影响因子：
3.1
作者：
Akerman, M;Shaked-Mishan, P;Zilberstein, D
通讯作者：
Zilberstein, D
影响因子：
4.4
作者：
Muleme, Helen M.;Reguera, Rosa M.;Uzonna, Jude E.
通讯作者：
Uzonna, Jude E.