Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 276, Issue 21, Pages 18551-18556Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M100223200
Keywords
-
Categories
Funding
- NHLBI NIH HHS [K08 HL004055, HL-03774, HL-04055, HL-24136] Funding Source: Medline
- NIDDK NIH HHS [DK-49786] Funding Source: Medline
Ask authors/readers for more resources
Dipeptidyl peptidase I (DPPI) is the sole activator in vivo of several granule-associated serine proteases of cytotoxic lymphocytes. In vitro, DPPI also activates mast cell chymases and tryptases, To determine whether DPPI is essential for their activation in vivo, we used enzyme histochemical and immunohistochemical approaches and solution-based activity assays to study these enzymes in tissues and bone marrow-derived mast cells (BMMCs) from DPPI +/+ and DPPI -/- mice. We find that DPPI -/- mast cells contain normal amounts of immunoreactive chymases but no chymase activity, indicating that DPPI is essential for chymase activation and suggesting that DPPI -/- mice are functional chymase knockouts. The absence of DPPI and chymase activity does not affect the growth, granularity, or staining characteristics of BMMCs and, despite prior predictions, does not alter IgE-mediated exocytosis of histamine. In contrast, the level of active tryptase (mMCP-6) in DPPI -/- BMMCs is 25% that of DPPI +/- BMMCs. These findings indicate that DPPI is not essential for mMCP-6 activation but does influence the total amount of active mMCP-6 in mast cells and therefore may be an important, but not exclusive mechanism for tryptase activation.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available