Abstract
Mutations in the neutrophil elastase (NE) gene have been postulated to interfere with normal intracellular trafficking of NE as an AP3-interacting membrane integrated protein and to cause severe congenital or cyclic neutropenia in humans. Here, we show that in U937 promonocytes NE is synthesized as a predominantly soluble proenzyme and is completely secreted in the presence of phorbol esters similarly to serglycin. Using chemical cross-linking NE is shown to be associated with serglycin as 34 kDa proenzyme in the trans-Golgi region of these cells indicating that it is delivered to lysosomes associated with serglycin.
MeSH terms
-
Ammonium Chloride / pharmacology
-
Cross-Linking Reagents / pharmacology
-
Glycoproteins / metabolism
-
Humans
-
Leukocyte Elastase / analysis
-
Leukocyte Elastase / metabolism*
-
Lysosomes / enzymology*
-
Monocytes / drug effects
-
Monocytes / enzymology
-
Monocytes / ultrastructure
-
Phorbol Esters / pharmacology
-
Protein Transport
-
Proteoglycans / analysis
-
Proteoglycans / metabolism*
-
Solubility
-
Tunicamycin / pharmacology
-
U937 Cells
-
Vesicular Transport Proteins / analysis
-
Vesicular Transport Proteins / metabolism*
-
trans-Golgi Network / enzymology
Substances
-
Cross-Linking Reagents
-
Glycoproteins
-
Phorbol Esters
-
Proteoglycans
-
Vesicular Transport Proteins
-
serglycin
-
Ammonium Chloride
-
Tunicamycin
-
Leukocyte Elastase