المؤلفون: Weng, Chenchun, Kosalka, Joanna, Berkyurek, Ahmet C., Stempor, Przemyslaw, Feng, Xuezhu, Mao, Hui, Zeng, Chenming, Li, Wen-Jun, Yan, Yong-Hong, Dong, Meng-Qiu, Morero, Natalia Rosalía, Zuliani, Cecilia, Barabas, Orsolya, Ahringer, Julie, Guang, Shouhong, Miska, Eric A.

المصدر: ISSN: 0890-9369 ; Genes & development, vol. 33, no. 1-2 (2019) p. 90-102.

مصطلحات موضوعية: PRDE-1, Ruby motif, SNPC, SNPC-4, TOFU-4, TOFU-5, U6 RNA, piRNA, snRNA

الوصف: Piwi-interacting RNAs (piRNAs) engage Piwi proteins to suppress transposons and nonself nucleic acids and maintain genome integrity and are essential for fertility in a variety of organisms. In Caenorhabditis elegans , most piRNA precursors are transcribed from two genomic clusters that contain thousands of individual piRNA transcription units. While a few genes have been shown to be required for piRNA biogenesis, the mechanism of piRNA transcription remains elusive. Here we used functional proteomics approaches to identify an upstream sequence transcription complex (USTC) that is essential for piRNA biogenesis. The USTC contains piRNA silencing-defective 1 (PRDE-1), SNPC-4, twenty-one-U fouled-up 4 (TOFU-4), and TOFU-5. The USTC forms unique piRNA foci in germline nuclei and coats the piRNA cluster genomic loci. USTC factors associate with the Ruby motif just upstream of type I piRNA genes. USTC factors are also mutually dependent for binding to the piRNA clusters and forming the piRNA foci. Interestingly, USTC components bind differentially to piRNAs in the clusters and other noncoding RNA genes. These results reveal the USTC as a striking example of the repurposing of a general transcription factor complex to aid in genome defense against transposons.

العلاقة: info:eu-repo/semantics/altIdentifier/pmid/30567997; https://archive-ouverte.unige.ch/unige:175520Test; unige:175520

الإتاحة: https://doi.org/10.1101/gad.319293.118Test
https://archive-ouverte.unige.ch/unige:175520Test

المؤلفون: Feng, XueZhu, Guang, ShouHong

المصدر: SCIENCE CHINA Life Sciences; Oct2013, Vol. 56 Issue 10, p937-943, 7p

مستخلص: Most eukaryotes employ a variety of mechanisms to defend the integrity of their genome by recognizing and silencing parasitic mobile nucleic acids. However, recent studies have shown that genomic DNA undergoes extensive rearrangements, including DNA elimination, fragmentation, and unscrambling, during the sexual reproduction of ciliated protozoa. Non-coding RNAs have been identified to program and regulate genome rearrangement events. In Paramecium and Tetrahymena, scan RNAs (scnRNAs) are produced from micronuclei and transported to vegetative macronuclei, in which scnRNA elicits the elimination of cognate genomic DNA. In contrast, Piwi-interacting RNAs (piRNAs) in Oxytricha enable the retention of genomic DNA that exhibits sequence complementarity in macronuclei. An RNA interference (RNAi)-like mechanism has been found to direct these genomic rearrangements. Furthermore, in Oxytricha, maternal RNA templates can guide the unscrambling process of genomic DNA. The non-coding RNA-directed genome rearrangements may have profound evolutionary implications, for example, eliciting the multigenerational inheritance of acquired adaptive traits. [ABSTRACT FROM AUTHOR]

: Copyright of SCIENCE CHINA Life Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)