| Popis: |
Normal function of all epithelia relies on the correct polarized localization of ion transport proteins, and malfunctions in the trafficking of these proteins to the plasma membrane contribute to numerous diseases. Na+, HCO3− cotransporter NBCn1 (SLC4A7) is a major regulator of pHi in most cell types with important functions in the cardiovascular system, the kidneys, and other organ systems. The dysfunction of NBCn1 is implicated in several diseases, includig hypertension and cancer. In particular, NBCn1 plays a central role in breast cancer. Despite the importance of NBCn1 in physiology and disease, very little is known about the regulation and roles of NBCn1. Specifically, there is a near-complete lack of knowledge regarding NBCn1 biosynthesis, trafficking, and degradation pathways. Prior to this study, our lab performed mass spectrometry analysis of interaction partners of, revealing several putative C-tail interactions candidates. In this study, we performed co-IP to validate these suggested interactions partners. We found that NBCn1 interacts with γ-adaptin, suggesting NBCn1 sorting to the membrane via AP-1 clathrin-coated vesicles. Morover, we foung that NBCn1 interacts with lateral polaity proteins LLGL-1 and DLG, suggesting a lateral targeting pattern for NBCb1. Lastly, we found that scaffold protein RACK1 interacts with NBCn1 and that the proximal 22 amino acids of the C-tail are sufficient for RACK1 interaction. |
