Figure 6. Activation of acyl CoA-dependent MEND without Ca transients.
(A) Pipette perfusion of mCoA (15 μM) without previously activating a Ca transient causes little or no endocytosis over 5 min (green square). Extracellular application of OAG (15 μM) for 1 to 2 min also has little or no effect, even after 6 min. With mCoA (15 μM) in the cytoplsamic solution, OAG initiates a decrease of membrane area that continues for several minutes after OAG is removed, amounting to 24% on average after 6 min. (B) Application of H2O2 (80 μM) for 4 min has little or no effect over 15 min in the absence of mCoA. With mCoA (15 μM) in the cytoplasmic solution, however, a large decrease of membrane area occurs when H2O2 is removed, amounting to 26% on average after 6 min. (C) MEND responses quantified as percent decrease of membrane area per min over 4 min. From left to right, the bar graphs quantify MEND caused by OAG, inhibition of OAG-induced MEND by PKC peptide 19–36 (1 μM in the pipette), MEND caused by H2O2, lack of effect of PKC peptide (19–35) on H2O2 MEND, and average MEND responses to H2O2 and OAG applied sequentially. (D) MEND in T-Rex-293 cells with inducible PLM expression. The bar graphs quantify the percent decrease of membrane area over 4 min after applying OAG. OAG-activated MEND is increased nearly three-fold when PLM expression has been induced for 24 hr.