protein targeting to membrane post-translational protein targeting to endoplasmic reticulum membrane posttranslational protein targeting to endoplasmic reticulum membrane SRP-independent endoplasmic reticulum protein-membrane targeting GO:0006620 posttranslational endoplasmic reticulum membrane targeting posttranslational protein targeting to ER membrane The targeting of proteins to a membrane that occurs after their translation. Some secretory proteins exhibit posttranslational transport into the endoplasmic reticulum (ER) lumen: they are synthesized in their entirety on free cytosolic ribosomes and then released into the cytosol, where they are bound by chaperones which keep them in an unfolded state, and subsequently are translocated across the ER membrane. posttranslational protein endoplasmic reticulum membrane targeting posttranslational endoplasmic reticulum protein-membrane targeting biological_process protein targeting to ER