L. major infection induces proteolysis of p130Cas and
PTP-PEST. A, fibroblasts positive and negative for PTP-PEST
expression were starved for 16 h in 0.05% heat-inactivated FBS/DMEM and
incubated in starvation medium without or with L. major at a ratio of
1:20 (cells:parasites) for the indicated duration. IB, immunoblot.
B, PTP-PEST-/- cells expressing WT PTP-PEST (clone B11WT)
were exposed to different ratios (cells:parasites) of L. major for 10
min. C, PTP-PEST-/- cells rescued with either empty vector
(clones B14V and B15V) or with the WT enzyme (clones B11WT and B118WT) were
maintained in starvation or regular media (nonstarved) 16 h prior to
treatment. Indicated clones were incubated with or without L. major
in the absence of serum or with media supplemented with 10%
heat-inactivated-FBS. Cell lysates were prepared and analyzed by
immunoblotting for p130Cas and PTP-PEST. Filled arrowheads identify
intact proteins, and open arrowheads point to cleavage products.
L.m, L. major; SS, serum-starved; NS, nonstarved or
in presence of serum. The values on the right correspond to molecular
mass in kDa.