HOXA2 activity regulation by cytoplasmic relocation, protein stabilization and post-translational modification

Publication date: Available online 16 July 2019Source: Biochimica et Biophysica Acta (BBA) - Gene Regulatory MechanismsAuthor(s): Noémie Deneyer, Laure Bridoux, Céline Bombled, Tamara Pringels, Isabelle Bergiers, Sébastien Pyr dit Ruys, Didier Vertommen, Jean-Claude Twizere, René RezsohazyAbstractHOX proteins are homeodomain transcription factors critically involved in patterning animal embryos and controlling organogenesis. While the functions of HOX proteins and the processes under their control begin to be well documented, the modalities of HOX protein activity regulation remain poorly understood. Here we show that HOXA2 interacts with PPP1CB, a catalytic subunit of the Ser/Thr PP1 phosphatase complex. This interaction co-localizes in the cytoplasm with a previously described HOXA2 interactor, KPC2, which belongs to the KPC E3 ubiquitin ligase complex. We provide evidence that HOXA2, PPP1CB and KPC2 define a molecularly and functionally interacting complex. Collectively, our experiments support that PPP1CB and KPC2 together inhibit the activity of HOXA2 by activating its nuclear export, but favored HOXA2 de-ubiquitination and stabilization thereby establishing a store of HOXA2 in the cytoplasm.

Source: Biochimica et Biophysica Acta (BBA) Gene Regulatory Mechanisms - July 17, 2019 Category: Genetics & Stem Cells Source Type: research