Alternative protein products with different carboxyl termini from a single class I gene, H-2Kb.
In addition to mRNA encoding the canonical form of the murine class I antigen H-2Kb (348 amino acid residues), mRNA that would encode a shortened form of H-2Kb (missing 9 amino acids from the C-terminus) has been identified in C57BL/6 spleen cells by RNase-protection studies. The alternative transcripts of H-2Kb arise through the use of different AG acceptor splice sites for exon VIII. The existence of a shortened H-2Kb protein was demonstrated by sequential immunoprecipitation. Lysates of spleen cells that had been labeled with [35S]methionine and [3H]histidine were precleared with rabbit anti-peptide serum reactive with the C-terminus of the canonical H-2Kb. The shortened form of H-2Kb was immunoprecipitated from this lysate with H-2Kb alloantiserum. Both forms of H-2Kb were isolated by NaDodSO4/PAGE. Tryptic peptide mapping confirmed that these molecules differed only at their C-terminus. The shortened form of H-2Kb is also found in a B-cell line (R8) but not in three cloned T-cell lines or in a T-cell lymphoma (EL4), suggesting that regulatory events are involved in producing the two forms of H-2Kb. Putative lariat branch points involved in these alternative splicing events for the 3' coding region of H-2 class I pre-mRNAs are proposed.
Lew
A M
AM
Margulies
D H
DH
Maloy
W L
WL
Lillehoj
E P
EP
McCluskey
J
J
Coligan
J E
JE
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D005796:Genes; D006183:H-2 Antigens / Q000235:genetics*; D008214:Lymphocytes / Q000276:immunology; D008285:Major Histocompatibility Complex; D051379:Mice; D008810:Mice, Inbred C57BL; D010446:Peptide Fragments / Q000032:analysis; D012333:RNA, Messenger / Q000235:genetics; D013154:Spleen / Q000276:immunology; D014357:Trypsin
D006183:H-2 Antigens; C032876:H-2Kb protein, mouse; D010446:Peptide Fragments; D012333:RNA, Messenger; D004247:DNA; D014357:Trypsin