Gillen Christopher M, Gao Yongping, Niehaus-Sauter Margaret M, Wylde Meredith R, Wheatly Michele G
Department of Biology, Kenyon College, Gambier, OH 43022, USA.
Comp Biochem Physiol B Biochem Mol Biol. 2008 Jun;150(2):170-6. doi: 10.1016/j.cbpb.2008.02.010. Epub 2008 Mar 4.
Eukaryotic elongation factor 1Bgamma (eEF1Bgamma) is a subunit of elongation factor 1 (EF1), which regulates the recruitment of amino acyl-tRNAs to the ribosome during protein synthesis in eukaryotes. In addition to structural roles within eEF1, eEF1Bgamma has properties which suggest sensory or regulatory activities. We have cloned eEF1Bgamma from axial abdominal muscle of freshwater crayfish, Procambarus clarkii. The predicted amino acid sequence has 66% identity to Locusta migratoria eEF1Bgamma and 65% identity to Artemia salina eEF1Bgamma. We measured eEF1Bgamma expression by real-time PCR, using the relative quantification method with 18s ribosomal RNA as an internal calibrator. eEF1Bgamma expression was lowest in gill, axial abdominal muscle, and hepatopancreas, and was highest in the antennal gland (5.7-fold above hepatopancreas) and cardiac muscle (7.8-fold above hepatopancreas). In axial abdominal muscle, eEF1Bgamma expression was 4.4-fold higher in premolt and 11.9 higher in postmolt compared to intermolt. In contrast, eEF1Bgamma was decreased or unchanged in epithelial tissues during pre- and postmolt. eEF1Bgamma expression in the hepatopancreas was 3.5-fold higher during intermolt compared to premolt and was unchanged in gill and antennal gland. No significant differences in eEF1Bgamma were found after 1 week of acclimation to 4 degrees C. These results show that eEF1Bgamma is regulated at the mRNA level with tissue-specific differences in expression patterns.
真核生物延伸因子1Bγ（eEF1Bγ）是延伸因子1（EF1）的一个亚基，在真核生物蛋白质合成过程中，它调节氨酰基tRNA与核糖体的结合。除了在eEF1中发挥结构作用外，eEF1Bγ还具有一些提示其具有传感或调节活性的特性。我们从淡水小龙虾克氏原螯虾的腹部轴肌中克隆了eEF1Bγ。预测的氨基酸序列与飞蝗的eEF1Bγ有66%的同一性，与卤虫的eEF1Bγ有65%的同一性。我们使用以18s核糖体RNA为内参的相对定量方法，通过实时PCR测定eEF1Bγ的表达。eEF1Bγ在鳃、腹部轴肌和肝胰腺中的表达最低，在触角腺（比肝胰腺高5.7倍）和心肌（比肝胰腺高7.8倍）中表达最高。在腹部轴肌中，与蜕壳间期相比，蜕皮前期eEF1Bγ的表达高4.4倍，蜕皮后期高11.9倍。相比之下，在蜕皮前和蜕皮后，上皮组织中的eEF1Bγ减少或不变。肝胰腺中eEF1Bγ在蜕壳间期的表达比蜕皮前期高3.5倍，在鳃和触角腺中则不变。在适应4摄氏度1周后，未发现eEF1Bγ有显著差异。这些结果表明，eEF1Bγ在mRNA水平受到调控，其表达模式存在组织特异性差异。
