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Hokkaido University Collection of Scholarly and Academic Papers >
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Circulating salmon 28- and 22-kDa insulin-like growth factor binding proteins (IGFBPs) are co-orthologs of IGFBP-1.
| Title: | Circulating salmon 28- and 22-kDa insulin-like growth factor binding proteins (IGFBPs) are co-orthologs of IGFBP-1. |
| Authors: | Shimizu, Munetaka Browse this author →KAKEN DB | | Kishimoto, Keisuke Browse this author | | Yamaguchi, Teppei Browse this author | | Nakano, Yusuke Browse this author | | Hara, Akihiko Browse this author | | Dickhoff, Walton W Browse this author |
| Keywords: | Insulin-like growth factor binding protein | | Salmon | | Identification | | Gene duplication | | Subfunction partitioning |
| Issue Date: | 1-Nov-2011 |
| Publisher: | Elsevier |
| Journal Title: | General and comparative endocrinology |
| Volume: | 174 |
| Issue: | 2 |
| Start Page: | 97 |
| End Page: | 106 |
| Publisher DOI: | 10.1016/j.ygcen.2011.08.005 |
| PMID: | 21888908 |
| Abstract: | Circulating insulin-like growth factor binding proteins (IGFBPs) play pivotal roles in stabilizing IGFs and regulating their availability to target tissues. In the teleost circulation, three major IGFBPs are typically detected by ligand blotting with molecular masses around 20-25, 28-32 and 40-45kDa. However, their identity is poorly established and often confused. We previously identified salmon 22- and 41-kDa forms as IGFBP-1 and -2b, respectively. In the present study, we cloned the cDNA of 28-kDa IGFBP from Chinook salmon (Oncorhynchus tshawytscha) as well as rainbow trout (Oncorhynchus mykiss) based on the partial N-terminal amino acid sequence of purified protein and identified it as an ortholog of IGFBP-1. Structural and phylogenetic analyses revealed that the 28-kDa IGFBP is more closely related to human IGFBP-1 and zebrafish IGFBP-1a than the previously identified salmon IGFBP-1 (i.e. 22-kDa IGFBP). We thus named salmon 28- and 22-kDa forms as IGFBP-1a and -1b, respectively. Salmon IGFBP-1a contains a potential PEST region involved in rapid protein turnover and phosphorylation sites typically found in mammalian IGFBP-1, although the PEST and phosphorylation scores are not as high as those of human IGFBP-1. There was a striking difference in tissue distribution patterns between subtypes; Salmon igfbp-1a was expressed in a variety of tissues while igfbp-1b was almost exclusively expressed in the liver, suggesting that IGFBP-1a has more local actions. Direct seawater exposure (osmotic stress) of Chinook salmon parr caused increases in both IGFBP-1s in plasma, while IGFBP-1b appeared to be more sensitive. The presence of two co-orthologs of IGFBP-1 in the circulation in salmon, and most likely in other teleosts, provides a good opportunity to investigate subfunction partitioning of duplicated IGFBP-1 during postnatal growth. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/47281 |
| Appears in Collections: | 水産科学院・水産科学研究院 (Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 清水 宗敬
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