Translocation of TCR alpha chains into the lumen of the endoplasmic reticulum and their degradation

Science. 1993 Mar 26;259(5103):1901-4. doi: 10.1126/science.8456316.

Abstract

After synthesis, the alpha chain of the T cell antigen receptor (TCR alpha) can form a complex with other TCR chains and move to the cell surface, or TCR alpha can undergo degradation in the endoplasmic reticulum (ER) if it remains unassembled. The mechanism of translocation and degradation in the ER is unclear. It was found that the putative transmembrane region of TCR alpha (alpha tm) was incompetent on its own to act as a transmembrane region. Molecules that contained alpha tm were translocated into the ER lumen and then underwent either rapid degradation or secretion, depending on the sequence of the cytoplasmic domain. A specific signal for ER degradation within alpha tm does not appear to be present.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • CD4 Antigens / chemistry
  • CD4 Antigens / genetics
  • CD4 Antigens / metabolism
  • Cytoplasm / metabolism
  • DNA / genetics
  • Endoplasmic Reticulum / metabolism*
  • Glycosylation
  • HeLa Cells / metabolism
  • Humans
  • Immunosorbent Techniques
  • Lipid Bilayers / metabolism
  • Macromolecular Substances
  • Mice
  • Molecular Sequence Data
  • Mutagenesis
  • Protein Structure, Secondary
  • Receptors, Antigen, T-Cell / chemistry
  • Receptors, Antigen, T-Cell / genetics
  • Receptors, Antigen, T-Cell / metabolism*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Transfection

Substances

  • CD4 Antigens
  • Lipid Bilayers
  • Macromolecular Substances
  • Receptors, Antigen, T-Cell
  • Recombinant Fusion Proteins
  • DNA