Fig. 7: Model of Xbp1 mRNA regulation by Ataxin-2 and Fbxo42.
From: Fbxo42 promotes the degradation of Ataxin-2 granules to trigger terminal Xbp1 signaling
Upon ER stress, Xbp1 mRNA is transcribed and progressively accumulates in Ataxin-2 (Atx-2) granules, where it is protected from degradation. Ataxin-2 binds Xbp1 mRNA, together with Poly(A)-binding protein (PABP). Fbxo42 binds to Ataxin-2, promoting the ubiquitylation (Ub) of Ataxin-2 and its degradation by the proteosome. Xbp1 mRNA is released from Ataxin-2 granules and is translated by the ribosome.
