TY - JOUR AV - public Y1 - 1990/// TI - Structure and biosynthesis of the signal-sequence receptor UR - https://archiv.ub.uni-heidelberg.de/volltextserver/8592/ ID - heidok8592 JF - European Journal of Biochemistry A1 - Prehn, Siegfried A1 - Herz, Joachim A1 - Hartmann, Enno A1 - Kurzchalia, Teymuras V. A1 - Frank, Rainer A1 - Römisch, Karin A1 - Dobberstein, Bernhard A1 - Rapoport, Tom A. N2 - The signal-sequence receptor (SSR) has previously been shown to be a component of the environment which nascent polypeptides meet on passage through the endoplasmic reticulum (ER) membrane. We report here on the primary structure of the SSR as deduced from cDNA clones and from direct protein sequencing. The glycoprotein is synthesized with a cleavable amino-terminal signal sequence and contains only one classical membrane-spanning segment. Its insertion into the ER membrane during biosynthesis depends on the function of the signal-recognition particle. SSR shows a remarkable charge distribution with the amino terminus being highly negatively charged, and the cytoplasmic carboxyl terminus positively charged. The SSR can be phosphorylated in its cytoplasmic tail both in intact cells and in a cell-free system, suggesting a regulation of its function. The localization of the protein in the ER membrane was confirmed by immunofluorescence microscopy. VL - 188 EP - 445 SP - 439 ER -