Urea transporter and glutamine synthetase regulation and localization in gulf toadfish gill
Urea transporter and glutamine synthetase regulation and localization in gulf toadfish gill
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海湾蟾蜍鳃中尿素转运蛋白和谷氨酰胺合成酶的调节和定位
DOI：
10.1242/jeb.015875
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发表时间：
2009
影响因子：
2.8
通讯作者：
P. Walsh
中科院分区：
文献类型：
--
作者：
M. McDonald;B. Vulesevic;S. Perry;P. Walsh
本研究的目的是研究循环皮质醇和尿素在支链谷氨酰胺合成酶(GS)转录调控中的作用，GS将NH3结合到谷氨酸中形成谷氨酰胺，而蟾鱼尿素转运蛋白TUT参与海湾蟾鱼尿素跨鳃排泄。在暴露于不同应激反应的处理中，检测了GS(有两种亚型，LGS和GGS)和TUT mRNA的表达和活性。此外，通过单独给予尿素或联合腹腔注射皮质类固醇II受体拮抗剂RU486来研究循环尿素在TUT调节中的作用。在注射皮质醇后，鳃特异的GS亚型(GGS)的mRNA表达上调了4.8倍，在更普遍的亚型(LGS)中也有类似的上调。此外，拥挤胁迫和外源皮质醇注入分别使蟾鱼尿素转运蛋白TUT的mRNA表达水平显著上调1.9倍和3.3倍。此外，研究发现，TUT对转录调节具有尿素敏感成分，该成分独立于循环皮质醇浓度。然而，GGS、LGS和TUT基因表达的变化与蛋白质活性的变化不一致。为了确定参与谷氨酰胺合成和尿素排泄的细胞类型(S)，我们尝试用原位杂交的方法对GGS、LGS和TUT进行定位。这项研究首次表明GGS和TUT的表达似乎发生在蟾鱼的鳃线粒体丰富的细胞中，这表明这些细胞发挥着谷氨酰胺生产和尿素排泄的联合作用，这可能对捕食者的逃避有意义。
SUMMARY The goal of the present study was to investigate the role of circulating cortisol and urea in the transcriptional regulation of branchial glutamine synthetase (GS), which incorporates NH3 into glutamate to form glutamine, and the toadfish urea transporter, tUT, which is involved in urea excretion across the gill of the gulf toadfish. GS (of which there are two isoforms, LGS and GGS) and tUT mRNA expression and activity were measured in toadfish exposed to treatments that would induce variable stress responses. In addition, the role of circulating urea in tUT regulation was investigated by infusing toadfish with urea alone or in combination with intraperitoneal injection of RU486, a corticosteroid type II receptor antagonist. There was a 4.8-fold upregulation in the mRNA expression of the gill-specific GS isoform (GGS) in response to cortisol infusion and a similar upregulation in the more ubiquitous isoform (LGS). Furthermore, there was a significant 1.9-fold and 3.3-fold upregulation in the mRNA expression of the toadfish urea transporter, tUT, in response to stress through crowding or exogenous cortisol loading through infusion, respectively. In addition, tUT was found to have a urea-sensitive component to transcriptional regulation that was independent of circulating cortisol concentrations. However, the changes measured in mRNA expression of GGS, LGS and tUT did not correspond with changes in protein activity. To determine the cell type(s) involved in glutamine production and urea excretion, we attempted to localize GGS, LGS and tUT using in situ hybridization. This study is the first to show that GGS and tUT expression appear to occur in gill mitochondria-rich cells of toadfish, suggesting that these cells play a combined glutamine production and urea excretion role, which may have implications for predator avoidance.
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DOI：
10.1681/asn.v133581
发表时间：
2002
期刊：
Journal of the American Society of Nephrology : JASN
影响因子：
--
作者：
Klein,JanetD;Rouillard,Patricia;Roberts,BrianR;Sands,JeffM
通讯作者：
Sands,JeffM
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DOI：
10.1681/asn.v10102076
发表时间：
1999
期刊：
Journal of the American Society of Nephrology : JASN
影响因子：
--
作者：
Klein,JD;Timmer,RT;Rouillard,P;Bailey,JL;Sands,JM
通讯作者：
Sands,JM
DOI：
10.1016/s0167-4781(00)00311-0
发表时间：
2001-03
期刊：
Biochimica et biophysica acta
影响因子：
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作者：
Yushi Nakayama;M. Naruse;Alexander Karakashian;Tao Peng;Jeff M. Sands;Serena M. Bagnasco
通讯作者：
Yushi Nakayama;M. Naruse;Alexander Karakashian;Tao Peng;Jeff M. Sands;Serena M. Bagnasco
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DOI：
10.1152/ajprenal.00262.2001
发表时间：
2002
期刊：
American journal of physiology. Renal physiology
影响因子：
--
作者：
Peng,Tao;Sands,JeffM;Bagnasco,SerenaM
通讯作者：
Bagnasco,SerenaM
原代大鼠星形胶质细胞中皮质酮反应性 mRNA。
DOI：
10.1016/0169-328x(94)90032-9
发表时间：
1994
期刊：
Brain research. Molecular brain research
影响因子：
--
作者：
O'Banion,MK;Young,DA;Bohn,MC
通讯作者：
Bohn,MC