The TGN38 glycoprotein contains two non-overlapping signals that mediate localization to the trans-Golgi network.
The membrane-spanning and cytoplasmic domains of CD4 and CD8 were replaced by those of TGN38. After transient expression in HeLa cells, the location of the hybrid proteins was determined using immunofluorescence and quantitative immuno-electron microscopy, FACS analysis and metabolic labeling. The membrane-spanning domain was found to contain a signal that localized hybrid proteins to the TGN. This was in addition to the signal previously identified in the cytoplasmic domain (Bos, K., C. Wraight, and K. Stanley. 1993. EMBO (Eur. Mol. Biol. Organ) J. 12:2219-2228. Humphrey, J. S., P. J. Peters, L. C. Yuan, and J. S. Bonifacino. 1993. J. Cell Biol. 120:1123-1135. Wong, S. H., and W. Hong. 1993. J. Biol. Chem. 268:22853-22862). The different properties of these two signals suggest that each operates by a different mechanism.
Ponnambalam
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Cell Biology Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London, United Kingdom.
Rabouille
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C
Luzio
J P
JP
Nilsson
T
T
Warren
G
G
D000595:Amino Acid Sequence; D001692:Biological Transport; D015704:CD4 Antigens / Q000235:genetics / Q000378:metabolism; D016827:CD8 Antigens / Q000235:genetics / Q000378:metabolism; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection
D015704:CD4 Antigens; D016827:CD8 Antigens; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; C072237:TGOLN2 protein, human