Piwi-piRNA interactions: Within the nucleus, this pathway is involved in DNA methylation (A), histone methylation of H3K9 through interactions with heterochromatin protein 1 (HP1) and H3K9 histone methyltransferase (B). The Piwi-piRNA pathway also interacts with the …

Aug 3, 2007 · Transient transfection of PIWI-like 4 (PIWIL4), only member of the PIWI-like family that was ubiquitously expressed in human tissues, induced histone H3 lysine 9 methylation at the p16 Ink4a (CDKN2A) locus.

Jan 1, 2014 · Piwi may directly recruit HP1a, which in turn recruits a histone methyltransferase (Su(var)3-9 is shown) that then deposits methyl groups on the unmethylated H3K9. Alternatively, Piwi may directly recruit the histone methyltransferase, and subsequently HP1a may then bind the methylated H3K9.

As previously mentioned, TW1P is needed for DNA elimination. Work has shown that DNA sequences to be eliminated show the heterochromatin marker H3K9 (Liu et al. 2004). Mutations that decrease H3K9 methylation show a decreased efficiency in DNA elimination.

Nov 1, 2015 · Using this assay and genome-wide profiling of the H3K9me3 mark, we demonstrate an integral role of Eggless/SetDB1 in piRNA-guided silencing and show that Su (var)3-9 contributes to spreading of the H3K9me3 mark to TE-flanking domains.

Aug 3, 2007 · Transient transfection of PIWI-like 4 (PIWIL4), only member of the PIWI-like family that was ubiquitously expressed in human tissues, induced histone H3 lysine 9 methylation at the p16(Ink4a) (CDKN2A) locus.

May 4, 2017 · Piwi embryonic expression is needed for dual-strand piRNA cluster identity establishment that is required, in ovaries, for cluster H3K9 trimethylation (and Rhino binding), piRNA production, transposon repression, and female fertility. Cluster identity is then maintained in a Piwi-independent manner.

Sep 1, 2007 · Genetic mosaic and RNA in situ analyses suggest that piwi expression in adjacent somatic cells regulates GSC division. piwi encodes a highly basic novel protein, well conserved during evolution.

In the nucleus, piRNA-loaded Piwi proteins recognize nascent transcripts of active TEs and induce local H3K9 trimethylation and co-transactional silencing (Klenov et al., 2011; LeThomas et al., 2013; Rozhkov et al., 2013; Sienski et al., 2012).

The piRNA-interacting protein Piwi and the HMG protein Maelstrom collaborate genome-wide to silence transcription of transposons in part through trimethylation of H3K9, which depends on Piwi. Silencing broadly affects the expression of genes neighboring the transposons, and Maelstrom restricts spreading of the repressive histone mark.