Fig. 6: CTSD deficiency impairs mTORC1 localization and activity at the lysosomal membrane. | Nature Communications

Fig. 6: CTSD deficiency impairs mTORC1 localization and activity at the lysosomal membrane.

From: Cathepsin D deficiency in mammary epithelium transiently stalls breast cancer by interference with mTORC1 signaling

Fig. 6

a Analysis of phosphorylated (p-p38 MAPK) and total p38 MAPK protein levels by Western blot (with TUBA as loading control) in Ctsd+/+ and Ctsd−/− PyMT cells cultured for 7–10 days in 10% FCS or 1% FCS medium. Representative of 2 (p-p38 MAPK) and 1 (p38 MAPK) independent experiments. b Analysis of phosphorylated (p-P70S6K and p-S6) and total P70S6K and S6 protein levels by Western blot (with TUBA as loading control) in 10% FCS, 1% FCS, and mTOR inhibitor Torin-treated Ctsd+/+ and Ctsd−/− PyMT cells. Representative of 2 ((p-)S6) and 3 ((p-)P70S6K) independent experiments. c Quantification of (p-)P70S6K Western blots as in b, plotted as p-P70S6K/P70S6K ratio relative to 10% FCS Ctsd+/+ (n = 3 independent experiments; two-sided one-sample and two-sample t-test). Pictures of 10% FCS (d), FCS- and amino acid (AA)-starved (e), and acutely AA-stimulated (f) Ctsd+/+ and Ctsd−/− PyMT cells stained for mTOR (green), LAMP1 (red), and DNA (blue). Zoom shows enlargement of indicated image area in merge+DNA. Bars, 10 μm. Representative of 2 independent experiments. g Quantification of mTOR/LAMP1 co-localization in d–f (n = 6 images for acutely AA-stimulated Ctsd+/+, n = 7 images for acutely AA-stimulated Ctsd−/− and 10% FCS, n = 8 images for w/o FCS, AA; two independent experiments; two-sided two-sample t-test). Bar charts show all data points with mean + SD and p-value. Source data are provided as a Source Data file.

Back to article page