Molecular cloning of the mouse mast cell protease-5 gene. A novel secretory granule protease expressed early in the differentiation of serosal mast cells.
cDNAs were isolated that encode mouse mast cell protease-5 (MMCP-5), an approximately 30,000 Mr serine protease stored in the secretory granules of serosal mast cells (SMC) and Kirsten sarcoma virus-immortalized mast cells. Based on the deduced amino acid sequences of these cDNAs, MMCP-5 is synthesized as a 247-amino acid preproenzyme composed of a novel 19-residue hydrophobic signal peptide, a Gly-Glu activation peptide not present in other mast cell chymases, and a 226-amino acid protein that represents the mature enzyme. MMCP-5 possesses a unique Asn residue in the substrate binding cleft at residue 176 and is highly basically charged. The MMCP-5 gene was isolated, sequenced, and found to belong to a distinct subset of chymase genes. Allelic variations of the MMCP-5 gene were also detected. MMCP-5 is expressed in bone marrow-derived mast cells (BMMC), Kirsten sarcoma virus-immortalized mast cells, and SMC, but not in gastrointestinal mucosal mast cells of helminth-infected mice. The abundant levels of MMCP-5 mRNA in immature BMMC indicate that this chymase is expressed relatively early during the differentiation of mast cells. MMCP-5 is the first chymase to be molecularly cloned from progenitor mast cells and is also the first chymase shown to be expressed preferentially in the SMC subclass.
Department of Medicine, Harvard Medical School, Boston, Massachusetts.
H P
HP
McNeil
K F
KF
Austen
L L
LL
Somerville
M F
MF
Gurish
R L
RL
Stevens
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D053818:Chymases; D003001:Cloning, Molecular; D003594:Cytoplasmic Granules / Q000201:enzymology*; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D008407:Mast Cells / Q000201:enzymology*; D051379:Mice; D008969:Molecular Sequence Data; D012697:Serine Endopeptidases / Q000235:genetics* / Q000378:metabolism; D013379:Substrate Specificity; D016385:TATA Box; D014158:Transcription, Genetic
D004247:DNA; D012697:Serine Endopeptidases; D053818:Chymases