Organelle-associated rRNA Degradation.

Cytosolic rRNAs are highly dynamic and can be degraded under conditions such as apoptosis, starvation and magnesium depletion. The degradation is also related to their specific localization, as fractions of cytosolic ribosomes are localized on the surfaces of intracellular organelles, such as endoplasmic reticulum (ER) and mitochondria. Such localized translation facilitates translocation of nascent proteins into these organelles co-translationally, contributing to fast responses to cellular stresses and precise regulations of the organelle. Here, we describe a protocol to establish the in organello system to investigate rRNA degradation on mitochondrial outer membrane or ER. The protocol consists of organelle isolation, rRNA degradation on organelles and agarose gel electrophoresis to examine the remaining rRNAs.