Li S, Ren J, Huang L
Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, Nanchang, China.
J Anim Breed Genet. 2007 Jun;124(3):133-8. doi: 10.1111/j.1439-0388.2007.00645.x.
Insulin-like growth factor-binding protein acid-labile subunit (IGFALS) is an important glycoprotein in the circulation complex for insulin-like growth factors-I and -II (IGFs). So far only a partial porcine IGFALS sequence is available. We herein report the isolation, characterization, polymorphism identification and expression analysis of the porcine IGFALS gene. A 2000-bp full-length cDNA sequence was determined with 5'- and 3'-Rapid Amplification of cDNA End (RACE) assay. It contains a 1821-bp open reading frame encoding a protein of 606 amino acids with a calculated molecular mass of 66 kDa and a theoretical isoelectric point of 6.89. The deduced IGFALS protein shares high identity (70-80%) with other mammalian IGFALS. We also obtained a full-length genomic DNA sequence of the gene. Similar to the other mammalian orthologues, particularly in terms of exon size and exon/intron boundaries, the porcine IGFALS gene spans a transcription unit of 2990 bp, consisting of two exons and one intron. Three single nucleotide polymorphisms (synonymous mutations) were identified in the DNA sequence. RT-PCR assays indicate that IGFALS is expressed ubiquitously in pigs and transcripts are particularly abundant in the liver, lung, white adipose tissue, prostate, epididymis, thyroid and bladder.
胰岛素样生长因子结合蛋白酸不稳定亚基（IGFALS）是胰岛素样生长因子-I和-II（IGFs）循环复合物中的一种重要糖蛋白。到目前为止，仅获得了部分猪IGFALS序列。我们在此报告猪IGFALS基因的分离、表征、多态性鉴定及表达分析。通过5'-和3'-cDNA末端快速扩增（RACE）测定法确定了一个2000 bp的全长cDNA序列。它包含一个1821 bp的开放阅读框，编码一个606个氨基酸的蛋白质，计算分子量为66 kDa，理论等电点为6.89。推导的IGFALS蛋白与其他哺乳动物的IGFALS具有高度同源性（70-80%）。我们还获得了该基因的全长基因组DNA序列。与其他哺乳动物的直系同源物相似，特别是在外显子大小和外显子/内含子边界方面，猪IGFALS基因跨越一个2990 bp的转录单元，由两个外显子和一个内含子组成。在DNA序列中鉴定出三个单核苷酸多态性（同义突变）。RT-PCR分析表明，IGFALS在猪体内广泛表达，转录本在肝脏、肺、白色脂肪组织、前列腺、附睾、甲状腺和膀胱中特别丰富。
