Streptococcus pneumoniae has been shown to utilize the platelet activating factor receptor for binding and invasion of host cells (Cundell, D. R., Gerard, N. P., Gerard, C., Idanpaan-Heikkila, I., and Tuomanen, E. I.(1995) Nature, in press). Because bacterial binding is in part carbohydrate dependent, and the human platelet-activating factor (PAF) receptor bears a single N-linked glycosylation sequence in the second extracellular loop, we undertook studies to determine the role of this epitope in PAF receptor function. Binding of pneumococci to COS cells transfected with the human PAF receptor is greatly reduced for a receptor mutant that bears no N-linked glycosylation site. Immunohistochemical and binding analyses show decreased expression of the non-glycosylated molecule on the cell membrane relative to the wild type receptor; however, metabolic labeling and immunopurification indicate it is synthesized intracellularly at a level similar to the native molecule. A mutant receptor encoding a functional glycosylation site at the NH terminus is better expressed at the cell surface compared with the non-glycosylated form, indicating that trafficking to the cell surface is facilitated by glycosylation, but its location is relatively unimportant. The binding affinity for PAF is not significantly effected by the presence or location of the carbohydrate, and variations in cell surface expression have little influence on signal transduction, as the non-glycosylated PAF receptor is equally effective for activation of phospholipase C as the native molecule. These data are supportive of pneumococcal binding on protein moiety(ies) of the PAF receptor and indicate that N-glycosylation facilitates expression of the protein on the cell membrane.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				J. Bestebroer, K. P. M. van Kessel, H. Azouagh, A. M. Walenkamp, I. G. J. Boer, R. A. Romijn, J. A. G. van Strijp, and C. J. C. de Haas Staphylococcal SSL5 inhibits leukocyte activation by chemokines and anaphylatoxins Blood, January 8, 2009; 113(2): 328 - 337. [Abstract] [Full Text] [PDF]

				M. Aponte, W. Jiang, M. Lakkis, M.-J. Li, D. Edwards, L. Albitar, A. Vitonis, S. C. Mok, D. W. Cramer, and B. Ye Activation of Platelet-Activating Factor Receptor and Pleiotropic Effects on Tyrosine Phospho-EGFR/Src/FAK/Paxillin in Ovarian Cancer Cancer Res., July 15, 2008; 68(14): 5839 - 5848. [Abstract] [Full Text] [PDF]

				V. O. Melnikova, A. A. Mourad-Zeidan, D. C. Lev, and M. Bar-Eli Platelet-activating Factor Mediates MMP-2 Expression and Activation via Phosphorylation of cAMP-response Element-binding Protein and Contributes to Melanoma Metastasis J. Biol. Chem., February 3, 2006; 281(5): 2911 - 2922. [Abstract] [Full Text] [PDF]

				J. N. Radin, C. J. Orihuela, G. Murti, C. Guglielmo, P. J. Murray, and E. I. Tuomanen {beta}-Arrestin 1 Participates in Platelet-Activating Factor Receptor-Mediated Endocytosis of Streptococcus pneumoniae Infect. Immun., December 1, 2005; 73(12): 7827 - 7835. [Abstract] [Full Text] [PDF]

				E. Neuendorf, A. Weber, A. Saalmueller, H. Schatzl, K. Reifenberg, E. Pfaff, and M. H. Groschup Glycosylation Deficiency at Either One of the Two Glycan Attachment Sites of Cellular Prion Protein Preserves Susceptibility to Bovine Spongiform Encephalopathy and Scrapie Infections J. Biol. Chem., December 17, 2004; 279(51): 53306 - 53316. [Abstract] [Full Text] [PDF]

				D. Geromin, J.-F. Bourge, A. Soulie, R. Pawliuk, C. Fleet, E. Michel, Y. Denizot, C. Berthou, P. Leboulch, F. Sigaux, et al. Glycoprotein 170 Induces Platelet-Activating Factor Receptor Membrane Expression and Confers Tumor Cell Hypersensitivity to NK-Dependent Cell Lysis J. Immunol., March 15, 2004; 172(6): 3604 - 3611. [Abstract] [Full Text] [PDF]

				A. M. Marrache, F. Gobeil Jr., S. G. Bernier, J. Stankova, M. Rola-Pleszczynski, S. Choufani, G. Bkaily, A. Bourdeau, M. G. Sirois, A. Vazquez-Tello, et al. Proinflammatory Gene Induction by Platelet-Activating Factor Mediated Via Its Cognate Nuclear Receptor J. Immunol., December 1, 2002; 169(11): 6474 - 6481. [Abstract] [Full Text] [PDF]

				Z. Zhang, S. C. Austin, and E. M. Smyth Glycosylation of the Human Prostacyclin Receptor: Role in Ligand Binding and Signal Transduction Mol. Pharmacol., September 1, 2001; 60(3): 480 - 487. [Abstract] [Full Text] [PDF]

				Y. Nagayama, E. Nishihara, H. Namba, S. Yamashita, and M. Niwa Identification of the Sites of Asparagine-Linked Glycosylation on the Human Thyrotropin Receptor and Studies on Their Role in Receptor Function and Expression J. Pharmacol. Exp. Ther., October 1, 2000; 295(1): 404 - 409. [Abstract] [Full Text]

				L.M. McManus and R.N. Pinckard PAF, a Putative Mediator of Oral Inflammation Critical Reviews in Oral Biology & Medicine, January 1, 2000; 11(2): 240 - 258. [Abstract] [Full Text] [PDF]

				R. T.-K. Pang, S. S.-M. Ng, C. H.-K. Cheng, M. H. Holtmann, L. J. Miller, and B. K.-C. Chow Role of N-Linked Glycosylation on the Function and Expression of the Human Secretin Receptor Endocrinology, November 1, 1999; 140(11): 5102 - 5111. [Abstract] [Full Text]

				S. Jayadev, R. D. Smith, G. Jagadeesh, A. J. Baukal, L. Hunyady, and K. J. Catt N-Linked Glycosylation Is Required for Optimal AT1a Angiotensin Receptor Expression in COS-7 Cells Endocrinology, May 1, 1999; 140(5): 2010 - 2017. [Abstract] [Full Text]

				K. Ray, P. Clapp, P. K. Goldsmith, and A. M. Spiegel Identification of the Sites of N-Linked Glycosylation on the Human Calcium Receptor and Assessment of Their Role in Cell Surface Expression and Signal Transduction J. Biol. Chem., December 18, 1998; 273(51): 34558 - 34567. [Abstract] [Full Text] [PDF]

				J.-L. Parent, C. L. Gouill, E. Escher, and M. Rola-Pleszczynski Identification of Transmembrane Domain Residues Determinant in the Structure-Function Relationship of the Human Platelet-activating Factor Receptor by Site-directed Mutagenesis J. Biol. Chem., September 20, 1996; 271(38): 23298 - 23303. [Abstract] [Full Text] [PDF]