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Identification and functional analysis of c.422_423InsT, a novel mutation of the HNF1A gene in a patient with diabetes

BACKGROUND: HNF1A gene regulates liver‐specific genes, and genes that have a role in glucose metabolism, transport, and secretion of insulin. HNF1A gene mutations are frequently associated with type 2 diabetes. HNF1A protein has three domains: the dimerization domain, the DNA‐binding domain, and the...

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Autores principales: Magaña‐Cerino, Jesús Miguel, Luna‐Arias, Juan P., Labra‐Barrios, María Luisa, Avendaño‐Borromeo, Bartolo, Boldo‐León, Xavier Miguel, Martínez‐López, Mirian Carolina
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241209/
https://www.ncbi.nlm.nih.gov/pubmed/28116330
http://dx.doi.org/10.1002/mgg3.261
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author Magaña‐Cerino, Jesús Miguel
Luna‐Arias, Juan P.
Labra‐Barrios, María Luisa
Avendaño‐Borromeo, Bartolo
Boldo‐León, Xavier Miguel
Martínez‐López, Mirian Carolina
author_facet Magaña‐Cerino, Jesús Miguel
Luna‐Arias, Juan P.
Labra‐Barrios, María Luisa
Avendaño‐Borromeo, Bartolo
Boldo‐León, Xavier Miguel
Martínez‐López, Mirian Carolina
author_sort Magaña‐Cerino, Jesús Miguel
collection PubMed
description BACKGROUND: HNF1A gene regulates liver‐specific genes, and genes that have a role in glucose metabolism, transport, and secretion of insulin. HNF1A gene mutations are frequently associated with type 2 diabetes. HNF1A protein has three domains: the dimerization domain, the DNA‐binding domain, and the trans‐activation domain. Some mutations in the dimerization or DNA‐binding domains have no influence on the normal allele, while others have dominant negative effects. The I27L, A98V, and S487N polymorphisms are common variants of the HNF1A gene; they have been found in T2D and non‐diabetic subjects. METHODS AND RESULTS: We searched for mutations in the first three exons of the HNF1A gen in an Amerindian population of 71 diabetic patients. DNA sequencing revealed the previously reported I27L polymorphism (c.79A>C) in 53% of diabetic patients and in 67% of the control group. Thus, the I27L/L27L polymorphism might be a marker of Amerindians. In addition, we found the c.422_423InsT mutation in the HNF1A gene of one patient, which had not been previously reported. This mutation resulted in a frame shift of the open reading frame and a new translation stop in codon 187, leading to a truncated polypeptide of 186 amino acids (Q141Hfs*47). This novel mutation affects the DNA‐binding capacity of the mutant HNF1A protein by EMSA; its intracellular localization by fluorescence and confocal microscopy, and a dominant‐negative effect affecting the DNA‐binding capacity of the normal HNF1A by EMSA. We also studied the homology modeling structure to understand the effect of this mutation on its DNA‐binding capacity and its dominant negative effect. CONCLUSION: The HNF1A Q141Hfs*47 mutant polypeptide has no DNA‐binding capacity and exerts a dominant negative effect on the HNF1A protein. Therefore, it might produce severe phenotypic effects on the expression levels of a set of β‐cell genes. Consequently, its screening should be included in the genetic analysis of diabetic patients after more functional studies are performed.
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spelling pubmed-52412092017-01-23 Identification and functional analysis of c.422_423InsT, a novel mutation of the HNF1A gene in a patient with diabetes Magaña‐Cerino, Jesús Miguel Luna‐Arias, Juan P. Labra‐Barrios, María Luisa Avendaño‐Borromeo, Bartolo Boldo‐León, Xavier Miguel Martínez‐López, Mirian Carolina Mol Genet Genomic Med Original Articles BACKGROUND: HNF1A gene regulates liver‐specific genes, and genes that have a role in glucose metabolism, transport, and secretion of insulin. HNF1A gene mutations are frequently associated with type 2 diabetes. HNF1A protein has three domains: the dimerization domain, the DNA‐binding domain, and the trans‐activation domain. Some mutations in the dimerization or DNA‐binding domains have no influence on the normal allele, while others have dominant negative effects. The I27L, A98V, and S487N polymorphisms are common variants of the HNF1A gene; they have been found in T2D and non‐diabetic subjects. METHODS AND RESULTS: We searched for mutations in the first three exons of the HNF1A gen in an Amerindian population of 71 diabetic patients. DNA sequencing revealed the previously reported I27L polymorphism (c.79A>C) in 53% of diabetic patients and in 67% of the control group. Thus, the I27L/L27L polymorphism might be a marker of Amerindians. In addition, we found the c.422_423InsT mutation in the HNF1A gene of one patient, which had not been previously reported. This mutation resulted in a frame shift of the open reading frame and a new translation stop in codon 187, leading to a truncated polypeptide of 186 amino acids (Q141Hfs*47). This novel mutation affects the DNA‐binding capacity of the mutant HNF1A protein by EMSA; its intracellular localization by fluorescence and confocal microscopy, and a dominant‐negative effect affecting the DNA‐binding capacity of the normal HNF1A by EMSA. We also studied the homology modeling structure to understand the effect of this mutation on its DNA‐binding capacity and its dominant negative effect. CONCLUSION: The HNF1A Q141Hfs*47 mutant polypeptide has no DNA‐binding capacity and exerts a dominant negative effect on the HNF1A protein. Therefore, it might produce severe phenotypic effects on the expression levels of a set of β‐cell genes. Consequently, its screening should be included in the genetic analysis of diabetic patients after more functional studies are performed. John Wiley and Sons Inc. 2016-11-30 /pmc/articles/PMC5241209/ /pubmed/28116330 http://dx.doi.org/10.1002/mgg3.261 Text en © 2016 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Articles
Magaña‐Cerino, Jesús Miguel
Luna‐Arias, Juan P.
Labra‐Barrios, María Luisa
Avendaño‐Borromeo, Bartolo
Boldo‐León, Xavier Miguel
Martínez‐López, Mirian Carolina
Identification and functional analysis of c.422_423InsT, a novel mutation of the HNF1A gene in a patient with diabetes
title Identification and functional analysis of c.422_423InsT, a novel mutation of the HNF1A gene in a patient with diabetes
title_full Identification and functional analysis of c.422_423InsT, a novel mutation of the HNF1A gene in a patient with diabetes
title_fullStr Identification and functional analysis of c.422_423InsT, a novel mutation of the HNF1A gene in a patient with diabetes
title_full_unstemmed Identification and functional analysis of c.422_423InsT, a novel mutation of the HNF1A gene in a patient with diabetes
title_short Identification and functional analysis of c.422_423InsT, a novel mutation of the HNF1A gene in a patient with diabetes
title_sort identification and functional analysis of c.422_423inst, a novel mutation of the hnf1a gene in a patient with diabetes
topic Original Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241209/
https://www.ncbi.nlm.nih.gov/pubmed/28116330
http://dx.doi.org/10.1002/mgg3.261
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