Signal Transducer and Activator of Transcription 6 Changes and Protein Frustration by Single Amino Acid Substitutions: Implications for Cancer Progression.

Abstract

Signal transducer and activator of transcription 6 (STAT6) is a multifunctional protein that plays critical functions in cell proliferation, apoptosis, differentiation, and angiogenesis. Mutations in STAT6 may contribute to the development of certain complex diseases such as cancer. This study examined single amino acid substitutions in STAT6 to pinpoint deleterious variants and their related structural and functional impairments. Data on STAT6 mutations were obtained from the Ensembl database and analyzed to evaluate the selected mutations for their pathogenicity and destabilizing or harmful effects. Specifically, we analyzed aggregation propensity, nonpacking density, and accessible surface area on the chosen mutations. The results suggest that seven out of eight mutations are less soluble, which might lead to aggregation, disrupt ordered helices, and alter strand propensity. Four mutations lay in the conserved regions of the protein, as revealed by the Consurf analysis. We found that three mutations, E318G, L365F, and R562H, change hydrophobic contacts and lead to frustration of STAT6, which can alter its stability, contributing to disease progression in cancer. In conclusion, these findings inform how single amino acid changes can destabilize STAT6. This has implications for cancer progression which warrants further experimental research.