Yeast importin-β is required for nuclear import of the Mig2 repressor
<p>Abstract</p> <p>Background</p> <p>Mig2 has been described as a transcriptional factor that in the absence of Mig1 protein is required for glucose repression of the <it>SUC2</it> gene. Recently it has been reported that Mig2 has two different subcellular l...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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BMC
2012-11-01
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| Series: | BMC Cell Biology |
| Online Access: | http://www.biomedcentral.com/1471-2121/13/31 |
| _version_ | 1811280174086356992 |
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| author | Fernández-Cid Alejandra Vega Montserrat Herrero Pilar Moreno Fernando |
| author_facet | Fernández-Cid Alejandra Vega Montserrat Herrero Pilar Moreno Fernando |
| author_sort | Fernández-Cid Alejandra |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Mig2 has been described as a transcriptional factor that in the absence of Mig1 protein is required for glucose repression of the <it>SUC2</it> gene. Recently it has been reported that Mig2 has two different subcellular localizations. In high-glucose conditions it is a nuclear modulator of several Mig1-regulated genes, but in low-glucose most of the Mig2 protein accumulates in mitochondria. Thus, the Mig2 protein enters and leaves the nucleus in a glucose regulated manner. However, the mechanism by which Mig2 enters into the nucleus was unknown until now.</p> <p>Results</p> <p>Here, we report that the Mig2 protein is an import substrate of the carrier Kap95 (importin-β). The Mig2 nuclear import mechanism bypasses the requirement for Kap60 (importin-α) as an adaptor protein, since Mig2 directly binds to Kap95 in the presence of Gsp1(GDP). We also show that the Mig2 nuclear import and the binding of Mig2 with Kap95 are not glucose-dependent processes and require a basic NLS motif, located between lysine-32 and arginine-37. Mig2 interaction with Kap95 was assessed <it>in vitro</it> using purified proteins, demonstrating that importin-β, together with the GTP-binding protein Gsp1, is able to mediate efficient Mig2-Kap95 interaction in the absence of the importin-α (Kap60). It was also demonstrated, that the directionality of Mig2 transport is regulated by association with the small GTPase Gsp1 in the GDP- or GTP-bound forms, which promote cargo recognition and release, respectively.</p> <p>Conclusions</p> <p>The Mig2 protein accumulates in the nucleus through a Kap95 and NLS-dependent nuclear import pathway, which is independent of importin-α in <it>Saccharomyces cerevisiae</it>.</p> |
| first_indexed | 2024-04-13T01:09:16Z |
| format | Article |
| id | doaj.art-bcf0f53e2a8b401cbbe4d74d65455f66 |
| institution | Directory Open Access Journal |
| issn | 1471-2121 |
| language | English |
| last_indexed | 2024-04-13T01:09:16Z |
| publishDate | 2012-11-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Cell Biology |
| spelling | doaj.art-bcf0f53e2a8b401cbbe4d74d65455f662022-12-22T03:09:14ZengBMCBMC Cell Biology1471-21212012-11-011313110.1186/1471-2121-13-31Yeast importin-β is required for nuclear import of the Mig2 repressorFernández-Cid AlejandraVega MontserratHerrero PilarMoreno Fernando<p>Abstract</p> <p>Background</p> <p>Mig2 has been described as a transcriptional factor that in the absence of Mig1 protein is required for glucose repression of the <it>SUC2</it> gene. Recently it has been reported that Mig2 has two different subcellular localizations. In high-glucose conditions it is a nuclear modulator of several Mig1-regulated genes, but in low-glucose most of the Mig2 protein accumulates in mitochondria. Thus, the Mig2 protein enters and leaves the nucleus in a glucose regulated manner. However, the mechanism by which Mig2 enters into the nucleus was unknown until now.</p> <p>Results</p> <p>Here, we report that the Mig2 protein is an import substrate of the carrier Kap95 (importin-β). The Mig2 nuclear import mechanism bypasses the requirement for Kap60 (importin-α) as an adaptor protein, since Mig2 directly binds to Kap95 in the presence of Gsp1(GDP). We also show that the Mig2 nuclear import and the binding of Mig2 with Kap95 are not glucose-dependent processes and require a basic NLS motif, located between lysine-32 and arginine-37. Mig2 interaction with Kap95 was assessed <it>in vitro</it> using purified proteins, demonstrating that importin-β, together with the GTP-binding protein Gsp1, is able to mediate efficient Mig2-Kap95 interaction in the absence of the importin-α (Kap60). It was also demonstrated, that the directionality of Mig2 transport is regulated by association with the small GTPase Gsp1 in the GDP- or GTP-bound forms, which promote cargo recognition and release, respectively.</p> <p>Conclusions</p> <p>The Mig2 protein accumulates in the nucleus through a Kap95 and NLS-dependent nuclear import pathway, which is independent of importin-α in <it>Saccharomyces cerevisiae</it>.</p>http://www.biomedcentral.com/1471-2121/13/31 |
| spellingShingle | Fernández-Cid Alejandra Vega Montserrat Herrero Pilar Moreno Fernando Yeast importin-β is required for nuclear import of the Mig2 repressor BMC Cell Biology |
| title | Yeast importin-β is required for nuclear import of the Mig2 repressor |
| title_full | Yeast importin-β is required for nuclear import of the Mig2 repressor |
| title_fullStr | Yeast importin-β is required for nuclear import of the Mig2 repressor |
| title_full_unstemmed | Yeast importin-β is required for nuclear import of the Mig2 repressor |
| title_short | Yeast importin-β is required for nuclear import of the Mig2 repressor |
| title_sort | yeast importin β is required for nuclear import of the mig2 repressor |
| url | http://www.biomedcentral.com/1471-2121/13/31 |
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