title: A region of the immunoglobulin-mu heavy chain necessary for forming pentameric IgM.
abstract: In order to define the molecular requirements for IgM pentamer formation, we have isolated several mutant hybridomas which produce predominantly monomeric IgM. For one such mutant, 102, we synthesized a cDNA clone of its mu-mRNA, and found an in-frame 39-bp deletion, which thus encodes a mu-chain lacking amino acids 550-562, a region spanning the fourth constant domain and the tail of the mu-chain. To prove that this deletion is sufficient to block pentamer formation, we used site-directed mutagenesis to construct a mu-gene lacking these 39 bp, and have shown that the expression of this altered mu-gene results in the production of monomeric IgM.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics; D004247:DNA; D005796:Genes; D005813:Genes, Synthetic; D006825:Hybridomas / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007075:Immunoglobulin M / Q000096:biosynthesis / Q000235:genetics*; D007148:Immunoglobulin mu-Chains / Q000235:genetics*; D051379:Mice; D011487:Protein Conformation; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000235:genetics
chemical_list: D000911:Antibodies, Monoclonal; D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D007148:Immunoglobulin mu-Chains; D012333:RNA, Messenger; D011994:Recombinant Proteins; D004247:DNA