Unstimulated (top panel) or stimulated (1 μM thapsigargin for 5 min; lower panel) Jurkat T cells were incubated for 20 min in the presence of FM1-43, then fixed and subjected to photoconversion. Note ribosomes bound to the ER and photoconversion reaction product at the PM in unstimulated cell (top panel). Note photoconversion reaction product at the PM and within the ER lumen in stimulated cell (lower panel). Bars, 200 nm.

Membrane Trafficking