Arginine methylation of Aubergine mediates Tudor binding and germ plasm localization

Abstract

Piwi proteins such as Drosophila Aubergine (Aub) and mouse Miwi are essential for germline development and for primordial germ cell (PGC) specification. They bind piRNAs and contain symmetrically dimethylated arginines (sDMAs), catalyzed by dPRMT5. PGC specification in Drosophila requires maternal inheritance of cytoplasmic factors, including Aub, dPRMT5, and Tudor (Tud), that are concentrated in the germ plasm at the posterior end of the oocyte. Here we show that Miwi binds to Tdrd6 and Aub binds to Tudor, in an sDMA-dependent manner, demonstrating that binding of sDMA-modified Piwi proteins with Tudor-domain proteins is an evolutionarily conserved interaction in germ cells. We report that in Drosophila tud 1 mutants, the piRNA pathway is intact and most transposons are not de-repressed. However, the localization of Aub in the germ plasm is severely reduced. These findings indicate that germ plasm assembly requires sDMA modification of Aub by dPRMT5, which, in turn, is required for binding to Tudor. Our study also suggests that the function of the piRNA pathway in PGC specification may be independent of its role in transposon control.

mRNP granules

“…For example, components of germ granules, such as Piwi-family argonautes, harbor methylated arginines that help recruit tudor domain-containing proteins. Interfering with this interaction can impair both localization of tudor-domain proteins, and the methylated proteins themselves, 48,49 as well as germ granule assembly. 50 Such interactions also underpin recruitment of tudor-domain proteins to stress granules.…”

Mitochondrial protein BmPAPI modulates the length of mature piRNAs

“…KPN), which we described previously (Kirino et al 2010), were immobilized on two flow cells of an avidin-coupled sensor chip (BioCap, SensiQ). For immobilization, 150 μL of a 10 μg/mL peptide solution in running buffer was injected onto the sensor surface at 470 or 430 response units (RUs).…”

PAPI, a novel TUDOR-domain protein, complexes with AGO3, ME31B and TRAL in the nuage to silence transposition

“…It has been reported that the Drosophila dPRMT5 gene encodes a protein arginine methyltransferase (PRMT) that specifically catalyzes symmetric dimethylation of arginine residues of PIWI proteins (Kirino et al, 2009). Mass spectrometry analyses have revealed that PIWI, but not AGO, subfamily proteins are arginine methylated at their N termini Nishida et al, 2009;Vagin et al, 2009), which is important for the recognition of specific TUDOR family proteins Kirino et al, 2010;Nishida et al, 2009;Reuter et al, 2009;Shoji et al, 2009;Vagin et al, 2009;Wang et al, 2009). For example, TUDOR, one of the Drosophila TUDORdomain-containing proteins, associates with AUB and AGO3 in an sDMA-dependent manner (Kirino et al, 2010;Nishida et al, 2009).…”

“…Mass spectrometry analyses have revealed that PIWI, but not AGO, subfamily proteins are arginine methylated at their N termini Nishida et al, 2009;Vagin et al, 2009), which is important for the recognition of specific TUDOR family proteins Kirino et al, 2010;Nishida et al, 2009;Reuter et al, 2009;Shoji et al, 2009;Vagin et al, 2009;Wang et al, 2009). For example, TUDOR, one of the Drosophila TUDORdomain-containing proteins, associates with AUB and AGO3 in an sDMA-dependent manner (Kirino et al, 2010;Nishida et al, 2009). The mouse TUDOR domain-containing proteins TDRD1, TDRD2 and TDRD9 also require the sDMA modification of the mouse PIWI proteins for their association Reuter et al, 2009;Shoji et al, 2009;Vagin et al, 2009;Wang et al, 2009).…”

“…In Drosophila, the sDMAs of three PIWI proteins (PIWI, AUB and AGO3) are specifically catalyzed by a protein methyltransferase (PRMT) encoded by the dPRMT5 (csul/dart5 -FlyBase) gene (Kirino et al, 2009). This modification is crucial for their interaction with TUDOR-domain-containing proteins Kirino et al, 2009;Kirino et al, 2010;Nishida et al, 2009;Reuter et al, 2009;Shoji et al, 2009;Vagin et al, 2009;Vasileva et al, 2009;Wang et al, 2009). Thus, sDMAs may reflect a molecular motif that is specific to PIWI subfamily proteins and key to understanding the action mechanism of PIWI proteins.…”