The GW182 protein colocalizes with mRNA degradation associated proteins hDcp1 and hLSm4 in cytoplasmic GW bodies: FIGURE 1.

Abstract

A novel cytoplasmic compartment referred to as GW bodies (GWBs) was initially identified using antibodies specific to a 182-kD protein termed GW182. GW182 was characterized by multiple glycine(G)-tryptophan(W) repeats and an RNA recognition motif (RRM) that bound a subset of HeLa cell messenger RNAs (mRNAs). The function of GWBs was not known; however, more recent evidence suggested similarities between GWBs and cytoplasmic structures that contain hLSm proteins and hDcp1, the human homolog to a yeast decapping enzyme subunit. In this study, we used antibodies to hLSm4 and hDcp1 to show that both of these markers of an mRNA degradation pathway colocalize to the same structures as GW182. Our studies demonstrate that GW182, hLSm4, and hDcp1 are found in the same cytoplasmic structures and suggest that GW182 is involved in the same mRNA processing pathway as hLSm4 and hDcp1.

Small Interfering RNA-mediated Silencing Induces Target-dependent Assembly of GW/P Bodies

“…GWB are named from the marker protein GW182, which contains multiple glycine (G) and tryptophan (W) repeats and a classic RNA binding domain at the carboxyl terminus (Eystathioy et al, 2002a). The mRNA decay factors/complexes found in GWB include the deadenylase Ccr4, the decapping complex Dcp1a/1b/Dcp2, the LSm1-7 complex, Ge-1 (also known as Hedls), rck/p54, and exonuclease Xrn1 (Bashkirov et al, 1997;van Dijk et al, 2002;Ingelfinger et al, 2002;Lykke-Andersen, 2002;Eystathioy et al, 2003;Cougot et al, 2004;Andrei et al, 2005;Yu et al, 2005;Fenger-Gron et al, 2005). GWB are physically juxtaposed to and transiently interact with stress granules (SG).…”

Control of translation and mRNA degradation by miRNAs and siRNAs: Table 1.

“…Specifically, the mammalian GW182 protein, a major component of P-bodies (Eystathioy et al 2003), has been found to colocalize and coimmunoprecipitate with Argonaute proteins (Jakymiw et al 2005;Liu et al 2005a). Similarly, a homolog of GW182 in C. elegans, referred to as Ain-1, was found to coimmunoprecipitate, and in some cases, colocalize with a member of the Argonaute family in C. elegans, Alg-1 (Ding et al 2005).…”

Endonuclease-mediated mRNA Decay Requires Tyrosine Phosphorylation of Polysomal Ribonuclease 1 (PMR1) for the Targeting and Degradation of Polyribosome-bound Substrate mRNA

“…This disrupts the structure of the translating mRNP, 1 and mRNA targeted for degradation becomes associated with a different set of proteins than those of the actively translating complex (2). In both yeast and mammalian cells, proteins involved in decapping and 5Ј-3Ј mRNA degradation are concentrated in discrete cytoplasmic foci, termed P-bodies (3), or GW bodies (4) for the presence of a protein rich in glycine and tryptophan residues. Deadenylated yeast mRNAs relocate from actively translating polysomes to these foci before degradation of the mRNA body.…”