Lecture 4 "Sequestration of mRNPs in protein homeostasis"

mRNA surveillance is the cell’s quality-control system for messenger RNAs. It detects defective or improperly processed mRNAs and routes them to degradation so they do not produce harmful proteins.

A: Exported mRNA is checked

B: Translation

C: mRNA is sent for celanup

• nonsense-mediated decay for premature stop codons

• no-go decay for ribosome stallin

• non-stop decay for missing stop codons.[oup +1]

  
  

• Storage

• degradation

• stress-related sequestration

• forms granules and p-bodies

Predominantly comprise proteins and RNA ssociated with translation initiation

• Translation initiation complex

• RNA-bidning proteins

• nuclear shuttling proteins

• involved in SG-PB action

• epigentic factors

Comprise proteins associated with mRNA degredation

• decapping and deadnylase enzyme complex

• epigenetic factor

• involved in SG-PB action

• nuclear shuttling proteins

• translation initiation complex

• fine tuning of the proteome in response to stress by selective sequestration (GAPDH, IGF2, ß-actin) or exclusion (HSP70, HSP90) of mRNAS

• storage of translationally repressed mRNAs in SGs and PBs until favorable condirions return

• Neurodegenerative diseases

• Cancer

• Viral infection

• Inflammatory diseases

• Ischemia