| Autor: |
Chew Shern L, Cook Alexandra, Tan Daniel SW |
| Jazyk: |
angličtina |
| Rok vydání: |
2002 |
| Předmět: |
|
| Zdroj: |
BMC Cell Biology, Vol 3, Iss 1, p 17 (2002) |
| Druh dokumentu: |
article |
| ISSN: |
1471-2121 |
| DOI: |
10.1186/1471-2121-3-17 |
| Popis: |
Abstract Background Alternative exons encode different isoforms of the human insulin-like growth factor-I (IGF-I) precursor without altering mature IGF-I. We hypothesized that the various IGF-I precursors may traffic IGF-I differently. Chimeric IGF-I precursors were made with green fluorescent protein (GFP) cloned between the signal and mature IGF-I domains. Results Chimeras containing exons 1 or 2 were located in the cytoplasm, consistent with a secretory pathway, and suggesting that both exons encoded functional signal peptides. Exon 5-containing chimeras localized to the nucleus and strongly to the nucleolus, while chimeras containing exon 6 or the upstream portion of exon 5 did not. Nuclear and nucleolar localization also occurred when the mature IGF-I domain was deleted from the chimeras, or when signal peptides were deleted. Conclusions We have identified a nucleolar localization for an isoform of the human IGF-I precursor. The findings are consistent with the presence of a nuclear and nucleolar localization signal situated in the C-terminal part of the exon 5-encoded domain with similarities to signals in several other growth factors. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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