Figure 7. Knockout of calpain correlates with enhanced EGFR expression and sustained MAPK signaling.

7.5 × 10⁴ WT or capns1 KO MTECs were seeded overnight in 60 mm dishes. The following day cells were washed with PBS and changed to serum-free media. MTECs were stimulated with 50 ng/mL of EGF for the indicated times, lysed in RIPA buffer and assessed by immunoblotting. (A) capns1 KO correlates with activation of the MAPK pathway in response to EGF. (B) Full length EGFR levels are elevated in capns1 KO MTECs after overnight serum starvation. (C) capns1 KO is associated with greater EGF-induced MEK1/2 phosphorylation. (D) capns1 KO is associated with greater EGF-induced ERK1/2 phosphorylation.