Temporal evaluation of eIF2α phosphorylation in HeLa and C33A grown in tryptophan-free media.

<p>HeLa and C33A cells were plated in complete media, which was replaced with tryptophan-free media 24 hours post-plating. Cells were harvested every 6 hours and used to make extracts that were evaluated by immunoblot using antibodies against eIF2α or eIF2α phosphorylated on serine 51 (p-eIF2α). Immunoblots against β-actin were performed as a loading control. Similar results were obtained from three independent experiments.