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Calmodulin-dependent nuclear import of HMG-box family nuclear factors: importance of the role of SRY in sex reversal

The HMG (high-mobility group)-box-containing chromatin-remodelling factor SRY (sex-determining region on the Y chromosome) plays a key role in sex determination. Its role in the nucleus is critically dependent on two NLSs (nuclear localization signals) that flank its HMG domain: the C-terminally loc...

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Autores principales: Kaur, Gurpreet, Delluc-Clavieres, Aurelie, Poon, Ivan K. H., Forwood, Jade K., Glover, Dominic J., Jans, David A.
Formato: Texto
Lenguaje:English
Publicado: Portland Press Ltd. 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2911679/
https://www.ncbi.nlm.nih.gov/pubmed/20528776
http://dx.doi.org/10.1042/BJ20091758
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author Kaur, Gurpreet
Delluc-Clavieres, Aurelie
Poon, Ivan K. H.
Forwood, Jade K.
Glover, Dominic J.
Jans, David A.
author_facet Kaur, Gurpreet
Delluc-Clavieres, Aurelie
Poon, Ivan K. H.
Forwood, Jade K.
Glover, Dominic J.
Jans, David A.
author_sort Kaur, Gurpreet
collection PubMed
description The HMG (high-mobility group)-box-containing chromatin-remodelling factor SRY (sex-determining region on the Y chromosome) plays a key role in sex determination. Its role in the nucleus is critically dependent on two NLSs (nuclear localization signals) that flank its HMG domain: the C-terminally located ‘β-NLS’ that mediates nuclear transport through Impβ1 (importin β1) and the N-terminally located ‘CaM-NLS’ which is known to recognize the calcium-binding protein CaM (calmodulin). In the present study, we examined a number of missense mutations in the SRY CaM-NLS from human XY sex-reversed females for the first time, showing that they result in significantly reduced nuclear localization of GFP (green fluorescent protein)–SRY fusion proteins in transfected cells compared with wild-type. The CaM antagonist CDZ (calmidazolium chloride) was found to significantly reduce wild-type SRY nuclear accumulation, indicating dependence of SRY nuclear import on CaM. Intriguingly, the CaM-NLS mutants were all resistant to CDZ's effects, implying a loss of interaction with CaM, which was confirmed by direct binding experiments. CaM-binding/resultant nuclear accumulation was the only property of SRY found to be impaired by two of the CaM-NLS mutations, implying that inhibition of CaM-dependent nuclear import is the basis of sex reversal in these cases. Importantly, the CaM-NLS is conserved in other HMG-box-domain-containing proteins such as SOX-2, -9, -10 and HMGN1, all of which were found for the first time to rely on CaM for optimal nuclear localization. CaM-dependent nuclear translocation is thus a common mechanism for this family of important transcription factors.
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spelling pubmed-29116792010-08-02 Calmodulin-dependent nuclear import of HMG-box family nuclear factors: importance of the role of SRY in sex reversal Kaur, Gurpreet Delluc-Clavieres, Aurelie Poon, Ivan K. H. Forwood, Jade K. Glover, Dominic J. Jans, David A. Biochem J Research Article The HMG (high-mobility group)-box-containing chromatin-remodelling factor SRY (sex-determining region on the Y chromosome) plays a key role in sex determination. Its role in the nucleus is critically dependent on two NLSs (nuclear localization signals) that flank its HMG domain: the C-terminally located ‘β-NLS’ that mediates nuclear transport through Impβ1 (importin β1) and the N-terminally located ‘CaM-NLS’ which is known to recognize the calcium-binding protein CaM (calmodulin). In the present study, we examined a number of missense mutations in the SRY CaM-NLS from human XY sex-reversed females for the first time, showing that they result in significantly reduced nuclear localization of GFP (green fluorescent protein)–SRY fusion proteins in transfected cells compared with wild-type. The CaM antagonist CDZ (calmidazolium chloride) was found to significantly reduce wild-type SRY nuclear accumulation, indicating dependence of SRY nuclear import on CaM. Intriguingly, the CaM-NLS mutants were all resistant to CDZ's effects, implying a loss of interaction with CaM, which was confirmed by direct binding experiments. CaM-binding/resultant nuclear accumulation was the only property of SRY found to be impaired by two of the CaM-NLS mutations, implying that inhibition of CaM-dependent nuclear import is the basis of sex reversal in these cases. Importantly, the CaM-NLS is conserved in other HMG-box-domain-containing proteins such as SOX-2, -9, -10 and HMGN1, all of which were found for the first time to rely on CaM for optimal nuclear localization. CaM-dependent nuclear translocation is thus a common mechanism for this family of important transcription factors. Portland Press Ltd. 2010-07-28 2010-08-15 /pmc/articles/PMC2911679/ /pubmed/20528776 http://dx.doi.org/10.1042/BJ20091758 Text en © 2010 The Author(s) The author(s) has paid for this article to be freely available under the terms of the Creative Commons Attribution Non-Commercial Licence (http://creativecommons.org/licenses/by-nc/2.5/) which permits unrestricted non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited. http://creativecommons.org/licenses/by-nc/2.5/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Kaur, Gurpreet
Delluc-Clavieres, Aurelie
Poon, Ivan K. H.
Forwood, Jade K.
Glover, Dominic J.
Jans, David A.
Calmodulin-dependent nuclear import of HMG-box family nuclear factors: importance of the role of SRY in sex reversal
title Calmodulin-dependent nuclear import of HMG-box family nuclear factors: importance of the role of SRY in sex reversal
title_full Calmodulin-dependent nuclear import of HMG-box family nuclear factors: importance of the role of SRY in sex reversal
title_fullStr Calmodulin-dependent nuclear import of HMG-box family nuclear factors: importance of the role of SRY in sex reversal
title_full_unstemmed Calmodulin-dependent nuclear import of HMG-box family nuclear factors: importance of the role of SRY in sex reversal
title_short Calmodulin-dependent nuclear import of HMG-box family nuclear factors: importance of the role of SRY in sex reversal
title_sort calmodulin-dependent nuclear import of hmg-box family nuclear factors: importance of the role of sry in sex reversal
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2911679/
https://www.ncbi.nlm.nih.gov/pubmed/20528776
http://dx.doi.org/10.1042/BJ20091758
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