The targeting of proteins to a membrane that occurs during translation. The transport of most secretory proteins, particularly those with more than 100 amino acids, into the endoplasmic reticulum lumen occurs in this manner, as does the import of some proteins into mitochondria. [ http://www.ncbi.nlm.nih.gov/pubmed/16896215 http://www.ncbi.nlm.nih.gov/pubmed/10512867 https://www.worldcat.org/search?q=bn%3A0716731363 ]