Structural highlights
Function
EXD1_BOMMO RNA-binding component of the PET complex, a multiprotein complex required for the processing of piRNAs during spermatogenesis. The piRNA metabolic process mediates the repression of transposable elements during meiosis by forming complexes composed of piRNAs and Piwi proteins and governs the methylation and subsequent repression of transposable elements, preventing their mobilization, which is essential for the germline integrity. The PET complex is required during the secondary piRNAs metabolic process for the PIWIL2 slicing-triggered loading of PIWIL4 piRNAs. In the PET complex, EXD1 probably acts as an RNA adapter. EXD1 is an inactive exonuclease.[1]
Publication Abstract from PubMed
PIWI-interacting RNAs (piRNAs) guide PIWI proteins to suppress transposons in the cytoplasm and nucleus of animal germ cells, but how silencing in the two compartments is coordinated is not known. Here we demonstrate that endonucleolytic slicing of a transcript by the cytosolic mouse PIWI protein MILI acts as a trigger to initiate its further 5'-->3' processing into non-overlapping fragments. These fragments accumulate as new piRNAs within both cytosolic MILI and the nuclear MIWI2. We also identify Exonuclease domain-containing 1 (EXD1) as a partner of the MIWI2 piRNA biogenesis factor TDRD12. EXD1 homodimers are inactive as a nuclease but function as an RNA adaptor within a PET (PIWI-EXD1-Tdrd12) complex. Loss of Exd1 reduces sequences generated by MILI slicing, impacts biogenesis of MIWI2 piRNAs, and de-represses LINE1 retrotransposons. Thus, piRNA biogenesis triggered by PIWI slicing, and promoted by EXD1, ensures that the same guides instruct PIWI proteins in the nucleus and cytoplasm.
PIWI Slicing and EXD1 Drive Biogenesis of Nuclear piRNAs from Cytosolic Targets of the Mouse piRNA Pathway.,Yang Z, Chen KM, Pandey RR, Homolka D, Reuter M, Janeiro BK, Sachidanandam R, Fauvarque MO, McCarthy AA, Pillai RS Mol Cell. 2016 Jan 7;61(1):138-52. doi: 10.1016/j.molcel.2015.11.009. Epub 2015, Dec 6. PMID:26669262[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Yang Z, Chen KM, Pandey RR, Homolka D, Reuter M, Janeiro BK, Sachidanandam R, Fauvarque MO, McCarthy AA, Pillai RS. PIWI Slicing and EXD1 Drive Biogenesis of Nuclear piRNAs from Cytosolic Targets of the Mouse piRNA Pathway. Mol Cell. 2016 Jan 7;61(1):138-52. doi: 10.1016/j.molcel.2015.11.009. Epub 2015, Dec 6. PMID:26669262 doi:http://dx.doi.org/10.1016/j.molcel.2015.11.009
- ↑ Yang Z, Chen KM, Pandey RR, Homolka D, Reuter M, Janeiro BK, Sachidanandam R, Fauvarque MO, McCarthy AA, Pillai RS. PIWI Slicing and EXD1 Drive Biogenesis of Nuclear piRNAs from Cytosolic Targets of the Mouse piRNA Pathway. Mol Cell. 2016 Jan 7;61(1):138-52. doi: 10.1016/j.molcel.2015.11.009. Epub 2015, Dec 6. PMID:26669262 doi:http://dx.doi.org/10.1016/j.molcel.2015.11.009
