Defective secretory-protein mRNAs take the RAPP.

Secretory proteins destined for the lumen of the endoplasmic reticulum are key regulators of cellular functions and are thus subject to several levels of quality control. A recent study finds that the earliest step in secretory protein biogenesis--binding of the signal recognition particle to the signal sequence of the nascent peptide--is subject to a quality control process termed RAPP for 'regulation of aberrant protein production'. This process involves AGO2 and mRNA degradation.