Characterisation of apoptosis-stimulating p53 binding protein 2 (ASPP2) as a new substrate for asparaginyl hydroxylation

摘要: Hydroxylation by Fe(II)- and 2-oxoglutarate-dependent dioxygenases is increasingly recognised as an important protein modification. FIH-1-dependent hydroxylation of HIF-α subunits has previously been shown to influence the interaction this with transcriptional co-activators thereby modulating HIF activity. Recently, another substrate group could be identified for FIH-1. All substrates new are hydroxylated within a highly conserved domain, ankyrin repeat domain (ARD). In our study, we single site FIH-1 ARD apoptosis-stimulating p53 binding 2 (ASPP2), N986, in vitro cells. In contrast, family member inhibitory ASPP (iASPP) was not at corresponding asparagine revealing distinct characteristics required despite rather low specificity reported Physiologic effects ASPP2 were studied cancer cells depleted lentiviral transduction. Interestingly, p53-dependent apoptosis which modulated well between affected silencing general, role endogenous induction chemotherapy-induced confirmed using wild-type addition, neither proliferation nor adhesion or migration substantially upon depletion. tight junction partitioning defective 3 homolog (Par-3) impaired suppression This found regulation polarity neuronal progenitor vivo formation maintenance junctions epithelial vitro. observed that Par-3 following FIH-1which leads changes intracellular localisation complex cell type dependent manner. These findings demonstrate first time impact on ARD-containing substrates. contrast where N803 prevents association co-activators, junctional both proteins triggered hydroxylation. Depletion incubation hydroxylase inhibitor dimethyloxalylglycine (DMOG) part disrupted interdependent Par-3. Although altered vitro, may affect integrity barrier function epithelia vivo. Thus further studies examine physiologic FIH-1-depletion. Furthermore, interesting study other types date all performed exclusively. Taken together, results interactions can modified likely apply indicating implications broad range cellular signalling pathways involved.