海豚铁蛋白H和L亚基的序列分析以及海豚铁蛋白基因可能的铁依赖性翻译调控

Sequence analysis of dolphin ferritin H and L subunits and possible iron-dependent translational control of dolphin ferritin gene.

作者信息

Takaesu Azusa, Watanabe Kiyotaka, Takai Shinji, Sasaki Yukako, Orino Koichi

机构信息

Laboratories of Veterinary Biochemistry, School of Veterinary Medicine, Kitasato University, Aomori 034-8628, Japan.

出版信息

Acta Vet Scand. 2008 Oct 27;50(1):42. doi: 10.1186/1751-0147-50-42.

DOI:10.1186/1751-0147-50-42

PMID:18954429

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2603009/

Abstract

BACKGROUND

Iron-storage protein, ferritin plays a central role in iron metabolism. Ferritin has dual function to store iron and segregate iron for protection of iron-catalyzed reactive oxygen species. Tissue ferritin is composed of two kinds of subunits (H: heavy chain or heart-type subunit; L: light chain or liver-type subunit). Ferritin gene expression is controlled at translational level in iron-dependent manner or at transcriptional level in iron-independent manner. However, sequencing analysis of marine mammalian ferritin subunits has not yet been performed fully. The purpose of this study is to reveal cDNA-derived amino acid sequences of cetacean ferritin H and L subunits, and demonstrate the possibility of expression of these subunits, especially H subunit, by iron.

METHODS

Sequence analyses of cetacean ferritin H and L subunits were performed by direct sequencing of polymerase chain reaction (PCR) fragments from cDNAs generated via reverse transcription-PCR of leukocyte total RNA prepared from blood samples of six different dolphin species (Pseudorca crassidens, Lagenorhynchus obliquidens, Grampus griseus, Globicephala macrorhynchus, Tursiops truncatus, and Delphinapterus leucas). The putative iron-responsive element sequence in the 5'-untranslated region of the six different dolphin species was revealed by direct sequencing of PCR fragments obtained using leukocyte genomic DNA.

RESULTS

Dolphin H and L subunits consist of 182 and 174 amino acids, respectively, and amino acid sequence identities of ferritin subunits among these dolphins are highly conserved (H: 99-100%, (99-->98) ; L: 98-100%). The conserved 28 bp IRE sequence was located -144 bp upstream from the initiation codon in the six different dolphin species.

CONCLUSION

These results indicate that six different dolphin species have conserved ferritin sequences, and suggest that these genes are iron-dependently expressed.

摘要

背景

铁储存蛋白——铁蛋白在铁代谢中起核心作用。铁蛋白具有储存铁和分离铁以保护铁催化的活性氧的双重功能。组织铁蛋白由两种亚基组成（H：重链或心型亚基；L：轻链或肝型亚基）。铁蛋白基因表达在铁依赖方式下受翻译水平调控，或在铁非依赖方式下受转录水平调控。然而，海洋哺乳动物铁蛋白亚基的测序分析尚未全面开展。本研究的目的是揭示鲸类铁蛋白H和L亚基的cDNA衍生氨基酸序列，并证明这些亚基，尤其是H亚基受铁诱导表达的可能性。

方法

通过对来自六种不同海豚物种（糙齿海豚、斜纹原海豚、灰海豚、大吻领航鲸、宽吻海豚和白鲸）血液样本制备的白细胞总RNA经逆转录-PCR产生的cDNA的聚合酶链反应（PCR）片段进行直接测序，对鲸类铁蛋白H和L亚基进行序列分析。通过对使用白细胞基因组DNA获得的PCR片段进行直接测序，揭示六种不同海豚物种5'-非翻译区的推定铁反应元件序列。