New evidence for endoplasmic reticulum and Golgi apparatus in rabbit reticulocytes.

The incorporation of 14C-galactose and 14C-fucose in rabbit reticulocytes obtained by bleeding anaemia and separated according to their stage of maturation was studied. Only the youngest reticulocytes were shown to incorporate the two sugars with galactosylation being three times higher. The glycosylation behaved different from the synthesis of membrane proteins with respect to the dependence on temperature and time. Among the newly synthesized membrane proteins the signal sequence receptor (SSR), a compound of the system addressing protein translocation, was detected immunologically.