In E. coli, the 105 nt regulatory sRNA RprA (RpoS regulatory
RNA A) stimulates RpoS synthesis by base-pairing in an
osmolarity-dependent manner in response to cell envelope
stress (Majdalani et al., 2002). Transcription of RprA is
regulated by the RcsC/RcsB phosphorelay system, found
previously to regulate capsule synthesis and the activity
of the promoter of ftsZ, the cell division gene. Note that
another study has shown that the osmolarity-dependent
turnover of RprA contributes to its own abundance
(Majdalani et al., 2002).