This review describes what is known about the way of insertion and translocation of membrane proteins and the factors that determine these structures. The translocation of proteins across the cytoplasmic membrane in prokaryotes and that across the endosplasmic reticulum membrane in eukaryotes are similar in that both require the sinyal peptide that is attached to the amino terminus of the proteins. In general, mebrane proteins reach their final target via the secretory (Sec) pathway which are called Sec-dependent proteins. However, it has become clear that a few membrane proteins are not involved in Sec-pathway and these are called Sec-independent proteins.

This review describes what is known about the way of insertion and translocation of membrane proteins and the factors that determine these structures. The translocation of proteins across the cytoplasmic membrane in prokaryotes and that across the endosplasmic reticulum membrane in eukaryotes are similar in that both require the sinyal peptide that is attached to the amino terminus of the proteins. In general, mebrane proteins reach their final target via the secretory (Sec) pathway which are called Sec-dependent proteins. However, it has become clear that a few membrane proteins are not involved in Sec-pathway and these are called Sec-independent proteins.