BIOL 200 Lecture Notes - Lecture 28: Transferrin Receptor, Sequence Motif, Granulocyte Macrophage Colony-Stimulating Factor
Document Summary
Lecture 28 - regulation of gene expression mrna stability. The stability of cytoplasmic mrnas varies widely within and between organisms: mrnas can be regulated post-transcriptionally, half life is an indication of how stable mrnas are. Half lives vary amongst mrna: some mrnas are very highly regulated. Trigger degradation/destabilization of target mrna: when a/u sequence is switched for a g/c sequence, goes back to a regular 10hr half life, mrnas are actively degraded based on certain sequences. Stability of some rnas can be regulated: the stability of the mammalian transferrin receptor tfr (which is needed for the import of iron into the cell) is regulated in response to intracellular iron concentration. Translation of some mrnas can be inhibited: ferritin is an intracellular protein that sequesters iron ions, thereby preventing the accumulation of toxic levels of free iron ions. High iron concentrations - ferritin acts as a sponge. Regulated by ires and ire-bps: ferritin mrna has similar stem loops in.
