Isolation, characterization, and transcription of the gene encoding mouse mast cell protease 7.
A gene that encodes mouse mast cell protease (mMCP) 7 (also known as mouse mast cell tryptase 2) was isolated by genomic cloning with a cDNA that encodes mMCP-6, a tryptase in serosal mast cells. cDNAs encoding mMCP-7 were isolated from a bone-marrow-derived mast cell cDNA library. The mMCP-7 gene spans 2.3 kilobases and contains five exons rather than six, as found in the mMCP-6 and human mast cell tryptase I genes. Comparison of the 5' end of the transcript with the genomic sequence indicated that the region corresponding to the first intron in the mMCP-6 and human tryptase I genes is not spliced during transcription of mMCP-7 mRNA because of a point mutation at the intron 1 acceptor splice site; this results in a 5' untranslated region of 195 nucleotides, which is longer than that of any other known mast cell-specific transcript. mMCP-7 is 71-76% homologous with mMCP-6 and with dog and human mast cell tryptases, and it is the most acidic mast cell protease, with an overall net charge of -10. RNA blot analyses revealed that the mMCP-7 gene is transcribed in bone-marrow-derived mast cells but is not transcribed in mature serosal mast cells or in mucosal mast cell-enriched intestinal tissue of Trichinella spiralis-infected mice. Transcription of the mMCP-7 gene by differentiating bone-marrow-derived mast cells occurred within 1 week of bone-marrow culture but decreased dramatically after 3 weeks. Thus, the mMCP-7 gene displays a number of unusual structural characteristics and is distinctive in its transient and selective expression in immature mast cells maintained in interleukin 3-enriched medium.
McNeil
H P
HP
Department of Medicine, Harvard Medical School, Boston, MA.
Reynolds
D S
DS
Schiller
V
V
Ghildyal
N
N
Gurley
D S
DS
Austen
K F
KF
Stevens
R L
RL
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D053818:Chymases; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D005796:Genes; D007438:Introns; D008407:Mast Cells / Q000201:enzymology*; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D012697:Serine Endopeptidases / Q000235:genetics*; D014158:Transcription, Genetic; D053802:Tryptases
D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; C509190:Tpsb2 protein, mouse; D004247:DNA; D012697:Serine Endopeptidases; C083294:chymase 2; D053818:Chymases; C509222:Tpsab1 protein, mouse; D053802:Tryptases