Retrieval of transmembrane proteins to the endoplasmic reticulum.
A COOH-terminal double lysine motif maintains type I transmembrane proteins in the ER. Proteins tagged with this motif, eg., CD8/E19 and CD4/E19, rapidly receive post-translational modifications characteristic of the intermediate compartment and partially colocalized to this organelle. These proteins also received modifications characteristic of the Golgi but much more slowly. Lectin staining localized these Golgi modified proteins to ER indicating that this motif is a retrieval signal. Differences in the subcellular distribution and rate of post-translational modification of CD8 maintained in the ER by sequences derived from a variety of ER resident proteins suggested that the efficiency of retrieval was dependent on the sequence context of the double lysine motif and that retrieval may be initiated from multiple positions along the exocytotic pathway.
Jackson
M R
MR
Department of Immunology, Scripps Research Institute, La Jolla, California 92037.
Nilsson
T
T
Peterson
P A
PA
D016475:3T3 Cells / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015704:CD4 Antigens / Q000378:metabolism*; D016827:CD8 Antigens / Q000378:metabolism*; D002451:Cell Compartmentation; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008954:Models, Biological; D008969:Molecular Sequence Data; D009841:Oligonucleotides; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins
D015704:CD4 Antigens; D016827:CD8 Antigens; D008565:Membrane Proteins; D009841:Oligonucleotides; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins