Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeres
Drosophila lacks telomerase and fly telomeres are elongated by occasional transposition of three specialized retroelements. Drosophila telomeres do not terminate with GC-rich repeats and are assembled independently of the sequence of chromosome ends. Recent work has shown that Drosophila telomeres a...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2013-05-01
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| Series: | Frontiers in Oncology |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fonc.2013.00112/full |
| _version_ | 1818109120895516672 |
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| author | Grazia Daniela Raffa Giovanni eCenci Laura eCiapponi Maurizio eGatti |
| author_facet | Grazia Daniela Raffa Giovanni eCenci Laura eCiapponi Maurizio eGatti |
| author_sort | Grazia Daniela Raffa |
| collection | DOAJ |
| description | Drosophila lacks telomerase and fly telomeres are elongated by occasional transposition of three specialized retroelements. Drosophila telomeres do not terminate with GC-rich repeats and are assembled independently of the sequence of chromosome ends. Recent work has shown that Drosophila telomeres are capped by the terminin complex, which includes the fast-evolving proteins HOAP, HipHop, Moi and Ver. These proteins are not conserves outside Drosophilidae and localize and function exclusively at telomeres, protecting them from fusion events. Other proteins required to prevent end-to-end fusion in flies include HP1, Eff/UbcD1, ATM, the components of the Mre11-Rad50-Nbs (MRN) complex, and the Woc transcription factor. These proteins do not share the terminin properties; they are evolutionarily conserved non-fast-evolving proteins that do not accumulate only telomeres and do not serve telomere-specific functions. We propose that following telomerase loss, Drosophila rapidly evolved terminin to bind chromosome ends in a sequence-independent manner. This hypothesis suggests that terminin is the functional analog of the shelterin complex that protects human telomeres. The non-terminin proteins are instead likely to correspond to ancestral telomere-associated proteins that did not evolve as rapidly as terminin because of the functional constraints imposed by their involvement in diverse cellular processes. Thus, it appears that the main difference between Drosophila and human telomeres is in the protective complexes that specifically associate with the DNA termini. We believe that Drosophila telomeres offer excellent opportunities for investigations on human telomere biology. The identification of additional Drosophila genes encoding non-terminin proteins involved in telomere protection might lead to the discovery of novel components of human telomeres. |
| first_indexed | 2024-12-11T02:26:13Z |
| format | Article |
| id | doaj.art-196fcbb8159a48b3b67949ed06af4d65 |
| institution | Directory Open Access Journal |
| issn | 2234-943X |
| language | English |
| last_indexed | 2024-12-11T02:26:13Z |
| publishDate | 2013-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Oncology |
| spelling | doaj.art-196fcbb8159a48b3b67949ed06af4d652022-12-22T01:23:54ZengFrontiers Media S.A.Frontiers in Oncology2234-943X2013-05-01310.3389/fonc.2013.0011249132Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeresGrazia Daniela Raffa0Giovanni eCenci1Laura eCiapponi2Maurizio eGatti3Sapienza Università di RomaSapienza Università di RomaSapienza Università di RomaSapienza Università di RomaDrosophila lacks telomerase and fly telomeres are elongated by occasional transposition of three specialized retroelements. Drosophila telomeres do not terminate with GC-rich repeats and are assembled independently of the sequence of chromosome ends. Recent work has shown that Drosophila telomeres are capped by the terminin complex, which includes the fast-evolving proteins HOAP, HipHop, Moi and Ver. These proteins are not conserves outside Drosophilidae and localize and function exclusively at telomeres, protecting them from fusion events. Other proteins required to prevent end-to-end fusion in flies include HP1, Eff/UbcD1, ATM, the components of the Mre11-Rad50-Nbs (MRN) complex, and the Woc transcription factor. These proteins do not share the terminin properties; they are evolutionarily conserved non-fast-evolving proteins that do not accumulate only telomeres and do not serve telomere-specific functions. We propose that following telomerase loss, Drosophila rapidly evolved terminin to bind chromosome ends in a sequence-independent manner. This hypothesis suggests that terminin is the functional analog of the shelterin complex that protects human telomeres. The non-terminin proteins are instead likely to correspond to ancestral telomere-associated proteins that did not evolve as rapidly as terminin because of the functional constraints imposed by their involvement in diverse cellular processes. Thus, it appears that the main difference between Drosophila and human telomeres is in the protective complexes that specifically associate with the DNA termini. We believe that Drosophila telomeres offer excellent opportunities for investigations on human telomere biology. The identification of additional Drosophila genes encoding non-terminin proteins involved in telomere protection might lead to the discovery of novel components of human telomeres.http://journal.frontiersin.org/Journal/10.3389/fonc.2013.00112/fullDrosophilatelomere fusiontelomere protectiontermininnon-terminin proteins |
| spellingShingle | Grazia Daniela Raffa Giovanni eCenci Laura eCiapponi Maurizio eGatti Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeres Frontiers in Oncology Drosophila telomere fusion telomere protection terminin non-terminin proteins |
| title | Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeres |
| title_full | Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeres |
| title_fullStr | Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeres |
| title_full_unstemmed | Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeres |
| title_short | Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeres |
| title_sort | organization and evolution of drosophila terminin similarities and differences between drosophila and human telomeres |
| topic | Drosophila telomere fusion telomere protection terminin non-terminin proteins |
| url | http://journal.frontiersin.org/Journal/10.3389/fonc.2013.00112/full |
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