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Chavez J, Murillo-Maldonado JM, Bahena V, Cruz AK, Castañeda-Sortibrán A, Rodriguez-Arnaiz R, Zurita M, Valadez-Graham V. dAdd1 and dXNP prevent genome instability by maintaining HP1a localization at Drosophila telomeres. Chromosoma 2017; 126:697-712. [PMID: 28688038 DOI: 10.1007/s00412-017-0634-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 06/16/2017] [Accepted: 06/19/2017] [Indexed: 12/16/2022]
Abstract
Telomeres are important contributors to genome stability, as they prevent linear chromosome end degradation and contribute to the avoidance of telomeric fusions. An important component of the telomeres is the heterochromatin protein 1a (HP1a). Mutations in Su(var)205, the gene encoding HP1a in Drosophila, result in telomeric fusions, retrotransposon regulation loss and larger telomeres, leading to chromosome instability. Previously, it was found that several proteins physically interact with HP1a, including dXNP and dAdd1 (orthologues to the mammalian ATRX gene). In this study, we found that mutations in the genes encoding the dXNP and dAdd1 proteins affect chromosome stability, causing chromosomal aberrations, including telomeric defects, similar to those observed in Su(var)205 mutants. In somatic cells, we observed that dXNP and dAdd1 participate in the silencing of the telomeric HTT array of retrotransposons, preventing anomalous retrotransposon transcription and integration. Furthermore, the lack of dAdd1 results in the loss of HP1a from the telomeric regions without affecting other chromosomal HP1a binding sites; mutations in dxnp also affected HP1a localization but not at all telomeres, suggesting a specialized role for dAdd1 and dXNP proteins in locating HP1a at the tips of the chromosomes. These results place dAdd1 as an essential regulator of HP1a localization and function in the telomere heterochromatic domain.
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Affiliation(s)
- Joselyn Chavez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, Mexico
| | - Juan Manuel Murillo-Maldonado
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, Mexico
| | - Vanessa Bahena
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, Mexico
| | - Ana Karina Cruz
- Laboratorio de Genética. Facultad de Ciencias, Universidad Nacional Autónoma de México, Av. Universidad 3000, Col. Copilco-Universidad, Ciudad de México, Mexico
| | - América Castañeda-Sortibrán
- Laboratorio de Genética. Facultad de Ciencias, Universidad Nacional Autónoma de México, Av. Universidad 3000, Col. Copilco-Universidad, Ciudad de México, Mexico
| | - Rosario Rodriguez-Arnaiz
- Laboratorio de Genética. Facultad de Ciencias, Universidad Nacional Autónoma de México, Av. Universidad 3000, Col. Copilco-Universidad, Ciudad de México, Mexico
| | - Mario Zurita
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, Mexico
| | - Viviana Valadez-Graham
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, Cuernavaca, Morelos, Mexico.
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