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Tipping, C.

Publications and source records attributed to Tipping, C..

2 recordsLinked to original sources

Loss of the Integrator and Nuclear Exosome Targeting complexes disrupts oogenesis and causes the emergenceof atypical transcripts in Drosophila

Nuclear RNA homeostasis depends on the balance of transcription, RNA processing, degradation, and transport between the nucleus and cytoplasm. RNA degradation directed by the Integrator, nuclear exosome targeting (NEXT), and nuclear exosome complexes controls the accumulation of aberrant nuclear RNA. Here, we report that Drosophila oogenesis requires the Integrator, NEXT, and nuclear exosome complexes. Depletion of Integrator, NEXT, or nuclear exosome components in Drosophila female germ cells causes infertility and accumulation of 3' extended snRNAs, promoter upstream transcripts (PROMPTs), and cryptic transcripts. Our data highlight the essential role of nuclear RNA degradation and processing in Drosophila oogenesis and provide a catalog of RNAs whose nuclear levels are regulated by these three complexes. We propose that Integrator, NEXT, and the nuclear exosome support oogenesis by ensuring that inappropriate transcription does not overwhelm the limited supply of proteins that bind, process, and traffic RNA.

molecular biology↗

The RNA-binding ATPase, Armitage, Couples piRNA Amplification in Nuage to Phased piRNA Production on Mitochondria

PlWI-interacting RNAs (piRNAs) silence transposons in Drosophila ovaries, ensuring female fertility. Two coupled pathways generate germline piRNAs: the ping-pong cycle, in which the PIWI proteins Aubergine and Ago3 increase the abundance of pre-existing piRNAs, and the phased piRNA pathway, which generates strings of tail-to-head piRNAs, one after another. Proteins acting in the ping-pong cycle localize to nuage, whereas phased piRNA production requires Zucchini, an endonuclease on the mitochondrial surface. Here, we report that Armitage (Armi), an RNA-binding ATPase localized to both nuage and mitochondria, links the ping-pong cycle to the phased piRNA pathway. Mutations that block phased piRNA production deplete Armi from nuage. Armi ATPase mutants cannot support phased piRNA production and inappropriately bind mRNA instead of piRNA precursors. We propose that Armi shuttles between nuage and mitochondria, feeding precursor piRNAs generated by Ago3 cleavage into the Zucchini-dependent production of Aubergine- and Piwi-bound piRNAs on the mitochondrial surface.

genetics↗