Nucleotide sequences of gene segments encoding membrane domains of immunoglobulin gamma chains.
The nucleotide sequences of the exons encoding membrane-bound IgG1, IgG2a, and IgG2b of mouse were determined and compared with the sequence of membrane-bound IgM. The sequences indicate that membrane-bound gamma chains bear an additional 71 residues at the COOH termini, including 17-residue acidic, 26-residue hydrophobic, and 28 residue hydrophilic portions. The hydrophobic portion, which seems to be anchored in the lipid bilayer of the membrane, is highly conserved among membrane-bound mu and gamma chains. We propose the presence of a membrane protein that recognizes the conserved hydrophobic segment and anchors the membrane-bound immunoglobulin. Comparison of the nucleotide sequences revealed another example of intervening sequence-mediated domain exchange around one of the membrane exons.
D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface / Q000276:immunology; D001483:Base Sequence; D002462:Cell Membrane / Q000276:immunology; D003001:Cloning, Molecular; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant; D005796:Genes; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007142:Immunoglobulin gamma-Chains / Q000235:genetics*; D051379:Mice
D000954:Antigens, Surface; D004274:DNA, Recombinant; D007143:Immunoglobulin Heavy Chains; D007142:Immunoglobulin gamma-Chains; D004262:DNA Restriction Enzymes