metabolism ultrastructure Animals COS Cells Cercopithecus Cercopithecus aethiops Cytoplasmic Granules ER stress Endoplasmic Reticulum Enzyme Inhibitors Eukaryotic Initiation Factor-2 HSP70 Heat-Shock Proteins HeLa cell Hela Cells Humans Mammalia Mice Microscopy, Confocal NIH 3T3 Cells Oxidative Stress Oxidative stress P bodies Polyribosomes Protein Biosynthesis Protein Structure, Tertiary RNA binding protein RNA, Small Interfering RNA-Binding Proteins Rats Silencing foci