Fig. 2: AKT1 phosphorylation of CASTOR1 promotes RNF167-mediated ubiquitination and degradation of CASTOR1. | Nature Communications

Fig. 2: AKT1 phosphorylation of CASTOR1 promotes RNF167-mediated ubiquitination and degradation of CASTOR1.

From: RNF167 activates mTORC1 and promotes tumorigenesis by targeting CASTOR1 for ubiquitination and degradation

Fig. 2

a Deprivation of arginine or leucine activated AKT and increased CASTOR1 phosphorylation at S14, whereas deprivation of FBS or total amino acids inactivated AKT and reduced CASTOR1 phosphorylation at S14. b CASTOR1 S14 phosphorylation was markedly reduced following alanine substitution (S14A). c AKT inhibition abolished CASTOR1 phosphorylation at S14 in vivo. d Recombinant AKT1 protein directly phosphorylated CASTOR1 protein in vitro. e, f AKT overexpression increased (e) while AKT1 knockdown decreased (f) CASTOR1 degradation. g, h AKT1 overexpression increased (g) and AKT1 knockdown decreased (h) CASTOR1 ubiquitination. i CASTOR1 S14D had increased ubiquitination level compared to WT and S14A. j, k Phosphorylation of CASTOR1 at S14 significantly increased its affinity to RNF167 (j), and quantifications of results from three independent experiments are presented (k). For k, data are presented as mean values ± SEM and P value was calculated by one-way ANOVA followed by Tukey post hoc test (n = 3 independent experiments). Blots in a–c, e–j are representatives of n = 3 independent experiments, and blots in d are representatives of n = 2 independent experiments. Source data are provided in Source data file.

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