Kucharski R, Maleszka R
Visual Sciences, Research School of Biological Sciences, The Australian National University, Canberra, ACT 0200, Australia.
Gene. 1998 May 12;211(2):343-9. doi: 10.1016/s0378-1119(98)00114-0.
We have cloned and sequenced a 1.68-kb cDNA encoding arginine kinase in the honey bee, Apis mellifera. The predicted protein shows a high level of identity to known arginine kinases in invertebrates and to other proteins belonging to the conserved family of ATP: guanidino phospho-transferases. The pattern of expression of arginine kinase has been investigated for the first time in various tissues including the brain, antennae and compound eye. Our results show that three isoforms of arginine kinase, transcribed from a single gene, are expressed in a characteristic pattern in major tissues of the honey bee. Arginine kinase mRNA is relatively abundant in the central nervous system and in the antennae. However, the highest level of expression, that is at least two to three times higher than in the brain, is found in the compound eye of the bee. By contrast, the levels of mRNAs encoding another metabolically important enzyme, alpha-glycerolphosphate dehydrogenase (alpha-GPDH), are low in the eye. These findings suggest that arginine kinase is an important component of the energy releasing mechanism in the visual system that has high and fluctuating energy demands. Furthermore, our results support the role of phosphagen kinases in energy transport in polarised cells and are consistent with the role of arginine kinase as an energy shuttle that delivers ATP generated by mitochondria to high energy-requiring processes, such as massive membrane turnover and pigment regeneration in the retina.
我们已经克隆并测序了蜜蜂（Apis mellifera）中一个编码精氨酸激酶的1.68 kb cDNA。预测的蛋白质与无脊椎动物中已知的精氨酸激酶以及属于ATP：胍基磷酸转移酶保守家族的其他蛋白质具有高度同源性。首次在包括脑、触角和复眼在内的各种组织中研究了精氨酸激酶的表达模式。我们的结果表明，从单个基因转录而来的三种精氨酸激酶同工型，在蜜蜂的主要组织中以特征性模式表达。精氨酸激酶mRNA在中枢神经系统和触角中相对丰富。然而，在蜜蜂的复眼中发现了最高水平的表达，其表达量比脑中至少高两到三倍。相比之下，编码另一种代谢重要酶α-甘油磷酸脱氢酶（α-GPDH）的mRNA水平在眼中较低。这些发现表明，精氨酸激酶是视觉系统能量释放机制的重要组成部分，视觉系统具有高且波动的能量需求。此外，我们的结果支持磷酸原激酶在极化细胞能量运输中的作用，并且与精氨酸激酶作为能量穿梭体的作用一致，该穿梭体将线粒体产生的ATP传递到高能量需求过程，如视网膜中的大量膜周转和色素再生。
