1983/01/01 by Wilhelm Stoffel, Emmi KRÜGER, Rainer Deutzmann · 1 citation
Biochemistry, Genetics and Molecular Biology · #Glycosylation and Glycoproteins Research #Endoplasmic Reticulum Stress and Disease #Lipid metabolism and biosynthesis #Signal peptide #Endoplasmic reticulum #Reticulocyte #Apolipoprotein B #Biochemistry #Amino acid #Translation (biology) #Messenger RNA #Signal recognition particle #Biology #Protein biosynthesis #Peptide sequence #Vesicle #Signal peptidase #Cholesterol #Gene
paper · doi:10.1515/bchm2.1983.364.1.227
openalex publication_date 1983/01/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/06/11
Human liver apolipoprotein AI and A II poly(A+) mRNA has been translated in the cell-free rabbit reticulocyte lysate system. The structures of the two primary translation products of these two main protein components of human serum high-density lipoprotein (HDL) have been characterized. The products of the synthesis in vitro are preproapolipoproteins. The signal sequence (pre-sequence) of the primary translation product of human apo AI mRNA consists of 18 amino acids, that of apo AII of 17 amino acids. The cotranslational translocation into dog microsomal vesicles is associated with the cleavage of these sequences by the signal peptidase releasing the proapolipoproteins AI and AII, both extended by an N-terminal hexapeptide. Preproapolipoprotein AII is synthesized in its monomeric form consisting of 100 amino acids. Pro-apo AII is present in the vesicles of the endoplasmic reticulum also as monomer. Sequencing of the radiolabelled signal sequences of both pre-forms revealed their strongly hydrophobic nature. Despite the high affinity of HDL-apolipoproteins for complex lipids their secretion requires these hydrophobic signal sequences for translocation. Internal recognition sequences in the native apoproteins are not responsible for the transmembrane transport.