Cloning and characterization of the cDNA for human airway trypsin-like protease.
Previously we isolated a trypsin-like enzyme designated human airway trypsin-like protease from the sputum of patients with chronic airway diseases. This paper describes the cDNA cloning, characterization of the primary protein structure deduced from the cDNA, and gene expression of this enzyme in various human tissues. We obtained an entire 1517-base pair sequence of cDNA with an open reading frame encoding a polypeptide with 418-amino acid residues. The polypeptide consisted of a 232-residue catalytic region and a 186-residue noncatalytic region with a hydrophobic putative transmembrane domain near the NH2 terminus. The polypeptide was suggested to be a type II integral membrane protein in which the COOH-terminal catalytic region is extracellular. Therefore, this protein is thought to be synthesized as a membrane-bound precursor and to mature to a soluble and active protease by limited proteolysis. It showed 29-38% identity in the sequence of the catalytic region with human hepsin, enteropeptidase, acrosin, and mast cell tryptase. The noncatalytic region had little similarity to other known proteins. In Northern blot analysis a transcript of 1.9 kilobases was detectable most prominently in the trachea among 17 human tissues examined.
Yamaoka
K
K
Teijin Institute for Biomedical Research, 4-3-2 Asahigaoka, Hino, Tokyo 191, Japan.
Masuda
K
K
Ogawa
H
H
Takagi
K
K
Umemoto
N
N
Yasuoka
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D012137:Respiratory System / Q000201:enzymology*; D012140:Respiratory Tract Diseases / Q000201:enzymology*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000235:genetics*; D012995:Solubility; D013183:Sputum
D018076:DNA, Complementary; D008565:Membrane Proteins; D005340:Fibrinogen; D012697:Serine Endopeptidases; C112256:human airway trypsin-like protease