ArreSTick motif controls β-arrestin-binding stability and extends phosphorylation-dependent β-arrestin interactions to non-receptor proteins

The binding and function of β-arrestins are regulated by specific phosphorylation motifs present in G protein-coupled receptors (GPCRs). However, the exact arrangement of phosphorylated amino acids responsible for establishing a stable interaction remains unclear. We employ a 1D sequence convolution model trained on GPCRs with established β-arrestin-binding properties. With this approach, amino acid motifs characteristic of GPCRs that form stable interactions with β-arrestins can be identified, a pattern that we name “arreSTick.” Intriguingly, the arreSTick pattern is also present in numerous non-receptor proteins. Using proximity biotinylation assay and mass spectrometry analysis, we demonstrate that the arreSTick motif controls the interaction between many non-receptor proteins and β-arrestin2. The HIV-1 Tat-specific factor 1 (HTSF1 or HTATSF1), a nuclear transcription factor, contains the arreSTick pattern, and its subcellular localization is influenced by β-arrestin2. Our findings unveil a broader role for β-arrestins in phosphorylation-dependent interactions, extending beyond GPCRs to encompass non-receptor proteins as well. [Display omitted] •ArreSTick is a sequence pattern characteristic of stable GPCR-β-arrestin interaction•Numerous other proteins possess the arreSTick pattern•β-arrestin2 regulates HTSF1 via binding to its arreSTick motif Tóth et al. developed a machine learning-based approach to identify sequence motifs in GPCRs, termed arreSTick, that mediate stable β-arrestin binding. They found that arreSTick is also present in many other proteins, suggesting that β-arrestins may regulate non-GPCR proteins through a phosphorylation-dependent mechanism, similar to its function in GPCRs.