| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
* Departments of Microbiology, Chemistry and
Biochemisty, and
Computer Science, Montana State University, Bozeman, Montana 59717
The N-formyl peptide receptor (FPR), a G protein-coupled receptor that binds proinflammatory chemoattractant peptides, serves as a model receptor for leukocyte chemotaxis. Recombinant histidine-tagged FPR (rHis-FPR) was purified in lysophosphatidyl glycerol (LPG) by Ni2+-NTA agarose chromatography to >95% purity with high yield. MALDI-TOF mass analysis (>36% sequence coverage) and immunoblotting confirmed the identity as FPR. The rHis-FPR served as an immunogen for the production of 2 mAbs, NFPR1 and NFPR2, that epitope map to the FPR C-terminal tail sequences, 305-GQDFRERLI-313 and 337-NSTLPSAEVE-346, respectively. Both mAbs specifically immunoblotted rHis-FPR and recombinant FPR (rFPR) expressed in Chinese hamster ovary cells. NFPR1 also recognized recombinant FPRL1, specifically expressed in mouse L fibroblasts. In human neutrophil membranes, both Abs labeled a 45–75 kDa species (peak Mr 
60 kDa) localized primarily in the plasma membrane with a minor component in the lactoferrin-enriched intracellular fractions, consistent with FPR size and localization. NFPR1 also recognized a band of Mr 40 kDa localized, in equal proportions to the plasma membrane and lactoferrin-enriched fractions, consistent with FPRL1 size and localization. Only NFPR2 was capable of immunoprecipitation of rFPR in detergent extracts. The recognition of rFPR by NFPR2 is lost after exposure of cellular rFPR to f-Met-Leu-Phe (fMLF) and regained after alkaline phosphatase treatment of rFPR-bearing membranes. In neutrophils, NFPR2 immunofluorescence was lost upon fMLF stimulation. Immunoblotting 60 kDa species, after phosphatase treatment of fMLF-stimulated neutrophil membranes, was also enhanced. We conclude that the region 337–346 of FPR becomes phosphorylated after fMLF activation of rFPR-expressing Chinese hamster ovary cells and neutrophils.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 This work was supported by U.S. Public Health Service Grants 2R01-AI26711, 2R01-AI22735 (to A.J.J.), R01-AI51726 (to H.M.M.), and the American Heart Association Scientist Development Grant 06302S3N (to R.M.T.).
2 Address correspondence and reprint requests to Dr. Algirdas Jesaitis, Montana State University, 109 Lewis Hall, Bozeman, MT 59717. E-mail address: umbaj{at}montana.edu
3 Abbreviations used in this paper: FPR, N-formyl peptide receptor; GPCR, G protein-coupled receptor; LPG, lysophosphatidyl glycerol; fMLF, f-Met-Leu-Phe; CNBr, cyanogen bromide; CHO, Chinese hamster ovary; DPBS, Dulbecco’s PBS; SAP, shrimp alkaline phosphatase; CTZ, c-terminal 337-FPR-350 peptide.
Related articles in The JI:
This article has been cited by other articles:
|
|
 |
|
  B. A. Babbin, A. J. Jesaitis, A. I. Ivanov, D. Kelly, M. Laukoetter, P. Nava, C. A. Parkos, and A. Nusrat Formyl Peptide Receptor-1 Activation Enhances Intestinal Epithelial Cell Restitution through Phosphatidylinositol 3-Kinase-Dependent Activation of Rac1 and Cdc42 J. Immunol., December 15, 2007; 179(12): 8112 - 8121. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
