Developmental expression of p107 mRNA and evidence for alternative splicing of the p107 (RBL1) gene product.
Expression of p107, a protein with homology to the retinoblastoma tumor suppressor (pRB), was monitored during murine development. Northern blot tissue surveys identified two transcripts of 4.9 and 2.4 kb that hybridized to a p107 cDNA clone. Expression of both transcripts was detected in fetal tissues, with particularly high levels in the liver and heart. In contrast, p107 transcripts were markedly decreased in most adult tissues examined. Molecular cloning analyses revealed that the 4.9- and 2.4-kb transcripts encoded proteins with deduced molecular masses of 119 and 68 kDa, respectively. Genetic mapping studies suggested that the two p107 transcripts arose by alternative splicing of a common precursor. The protein encoded by the 2.4-kb transcript lacks the spacer and B motif of the "pocket domain," a region of homology between p107 and pRB that is required for binding to cell cycle regulatory proteins. Structural modifications resulting from alternative splicing may thus confer functional diversity upon the 119- and 68-kDa proteins.
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D018076:DNA, Complementary / Q000032:analysis; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D050720:Retinoblastoma-Like Protein p107
D018076:DNA, Complementary; D009687:Nuclear Proteins; D012333:RNA, Messenger; C489485:Rbl1 protein, mouse; D050720:Retinoblastoma-Like Protein p107