Interaction proteomics of wildtype SLC16A6 (MCT7) and phospho-variants

ABSTRACT: The solute carrier (SLC) transporter superfamily are important coordinators of metabolic and cellular homeostasis. Despite their importance for cellular homeostasis, SLCs remain a largely understudied group of proteins regarding their protein interactome. Thus, we conducted a largescale interactome proteomics study to characterize the interactome of roughly 400 of the 450 superfamily members. Within this study, we found that the monocarboxylate transporter SLC16A6 (MCT7) shows a unique interaction with CUL1 subunit and two F-box adaptor proteins BTRC and FBXW11. Sequence analysis revealed a potential phospho-degron sequence in the cytosolic loop of SLC16A6 (D239 to T245), like the consensus phospho-degron sequence (DSG-X(2,3,4)-S/T) recognized by the two adaptor proteins. To validate the phospho-degron, we generated single point variants of WT SLC16A6 that either potentially mimic phosphorylation (S240D, T245E) or prevent phosphorylation (phospho-dead). By comparing the interactome of the phospho-mutants against that of WT SLC16A6, we validated that the binding of phospho-dead mutants to SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex members was reduced, whereas the T245E phospho-mutant let to a slight increase in binding to the SCF protein complex. Through additional functional validations with protein stability assays and RNAi treatment of adaptors, we showed that SLC16A6 abundance is regulated by the SCF-complex through a phospho-degron.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Kidney Cell

SUBMITTER: Fabian Frommelt  

LAB HEAD: Giulio Superti-Furga

PROVIDER: PXD055141 | Pride | 2025-03-03

REPOSITORIES: Pride