Sequence, biogenesis, and function of diverse small RNA classes bound to the Piwi family proteins of Tetrahymena thermophila
| Autor: | Leath A. Tonkin, Kathleen Collins, Brandon Hogstad, Ravi Sachidanandam, Colin D. Malone, Gregory J. Hannon, Mary T. Couvillion, Suzanne R. Lee |
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| Jazyk: | angličtina |
| Rok vydání: | 2009 |
| Předmět: |
Small RNA
Pseudogene Molecular Sequence Data Protozoan Proteins Piwi-interacting RNA Tetrahymena thermophila Genetics Animals Gene Expressed Sequence Tags biology Sequence Analysis RNA Twist-Related Protein 1 Tetrahymena Gene Expression Regulation Developmental Argonaute biology.organism_classification RNA silencing MicroRNAs Transfer RNA RNA Protozoan Developmental Biology Research Paper Microsatellite Repeats Protein Binding |
| Popis: | PAZ/PIWI domain (PPD) proteins carrying small RNAs (sRNAs) function in gene and genome regulation. The ciliate Tetrahymena thermophila encodes numerous PPD proteins exclusively of the Piwi clade. We show that the three Tetrahymena Piwi family proteins (Twis) preferentially expressed in growing cells differ in their genetic essentiality and subcellular localization. Affinity purification of all eight distinct Twi proteins revealed unique properties of their bound sRNAs. Deep sequencing of Twi-bound and total sRNAs in strains disrupted for various silencing machinery uncovered an unanticipated diversity of 23- to 24-nt sRNA classes in growing cells, each with distinct genetic requirements for accumulation. Altogether, Twis distinguish sRNAs derived from loci of pseudogene families, three types of DNA repeats, structured RNAs, and EST-supported loci with convergent or paralogous transcripts. Most surprisingly, Twi7 binds complementary strands of unequal length, while Twi10 binds a specific permutation of the guanosine-rich telomeric repeat. These studies greatly expand the structural and functional repertoire of endogenous sRNAs and RNPs. |
| Databáze: | OpenAIRE |
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