Signal Recognition Particle 19kDa (SRP19)

The signal recognition particle (SRP) is a ribonucleoprotein complex that mediates the targeting of proteins to the endoplasmic reticulum (ER). SRP has at least 3 distinct functions that can be associated with the protein subunits: signal recognition, translational arrest, and ER membrane targeting by interaction with the docking protein. Sequence analysis showed that SRP19 contains a very basic C-terminal domain of 7 lysine residues interrupted by 2 glycine residues. Northern blot analysis revealed expression of a 0.9 kb transcript in HeLa cells. SDS-PAGE analysis showed that SRP19 is expressed as a 19-kD protein, identical in size to canine SRP19. Functional analysis determined that the SRP19 protein binds to 7SL RNA in canine pancreas.