Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dipeptidyl aminopeptidase II (DAP II) was demonstrated cytochemically in rat peritoneal mast cells. The bright red reaction product in smears of peritoneal wash fluid tended to be localized in one to eight granules in the perinuclear region of the cell. This finding was confirmed at the electron microscopic level, where a small proportion of the granules, most often located near the nucleus, revealed electron opacity indicative of DAP II. Focal areas in the nuclear envelope densified by DAP II reaction product resembled reactive foci observed previously in the nuclear envelope of peritoneal macrophages. In mast cells exposed 1 to 2 hours to phosphate-buffered saline containing horseradish-peroxidase--coated colloidal gold, the spherules of gold were internalized and transported exclusively to the DAP II-reactive granules. Their content of endocytosed gold thus identified DAP II-reactive granules as secondary lysosomes of heterophagic nature. Mast cells induced to release their granules by stimulation with the divalent cation ionophore A23187 retained exclusively those granules possessing DAP II or acid phosphatase reactivity. This selective granule retention after ionophore exposure further differentiated granules with DAP II reactivity from the other non-reactive mast cell granules, presumably indicating a difference between the limiting membrane of granules that are converted to secondary lysosomes and the membrane of those that are not altered and persist as primary lysosomes. Demonstration of the DAP II reactivity in a minority of mast cell granules and of the heterophagic nature of these granules provides evidence that tissue mast cells in vivo function in endocytic activity by transporting material of extrinsic origin to some of their granules which are thereby transformed to heterophagic bodies or constitute previously existing heterophagosomes.
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PMID:The heterophagic granules of mast cells: dipeptidyl aminopeptidase II activity and resistance to exocytosis. 42 34

The content of soluble protein, nonspecific esterase, dipeptidyl aminopeptidase II (DAP II), and proteinase inhibitors was compared for alveolar (AM) and peritoneal (PM) wash cells of rats. The cells present in the wash fluids were 85-90% macrophages in the peritoneal wash and 95% in the alveolar wash. Macromolecular components were resolved from whole cell homogenates by polyacrylamide gel isoelectric focusing (PAGIF) on horizontal gels and were identified cytochemically. Banding patterns clearly indicated a larger number of esterase zones in peritoneal compared to alveolar macrophages and ten previously unrecognized isozymes of DAP II in peritoneal macrophages with only three evident in their alveolar counterparts. (On whole blood smears, these cytochemically demonstratable enzymes were limited to macrophages, although DAP II was seen also in some mast cell granules). A protein band similar to the M6 band of alpha-1-antitrypsin in human serum was seen both in alveolar and peritoneal wash preparations. In addition, nine other major trypsin-binding protein bands were observed in the peritoneal macrophages, including two bands not observed in the alveolar macrophage extracts.
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PMID:Comparisons of alveolar and peritoneal macrophages: soluble protein, esterase, dipeptidyl aminopeptidase II, and proteinase inhibitor. 699 69