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Prepublished online as a Blood First Edition Paper on February 13, 2003; DOI 10.1182/blood-2002-07-2271. This Article Full Text (PDF) All Versions of this Article: 2002-07-2271v1 101/11/4615    most recent Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Santini, V. Articles by Schreiber, A. D Search for Related Content PubMed PubMed Citation Articles by Santini, V. Articles by Schreiber, A. D Social Bookmarking                   What's this? Submitted July 31, 2002 Accepted January 16, 2003 The Carboxyterminal Region of the Granulocyte-Colony Stimulating Factor Receptor Transduces a Phagocytic Signal Valeria Santini*, Barbara Scappini, Zena K Indik, Antonella Gozzini, Pierluigi Rossi Ferrini, and Alan D Schreiber Dept of Hematology, University of Florence, Firenze, Italy Dept of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA * Corresponding author; email: santini{at}unifi.it. Granulocyte colony stimulating factor (G-CSF) induces proliferation, maturation and functional activities of myeloid progenitors and mature neutrophils through a specific receptor, the G-CSF-R. The different signals are mediated by distinct regions of the cytoplasmic domain of G-CSF-R, but the precise role of each region has not yet been fully clarified. We evaluated the involvement of Syk kinase, essential in mediating phagocytic signals by Fc receptors, in G-CSF induced phagocytosis, employing murine myeloid 32D cells transfected with WT hG-CSF-R or with a G-CSF-R mutant truncated at cytoplasmic amino acid 715. The G-CSF-R mutant lacks the ITAM-like motif, putative binding site for Syk. Following treatment of WT hG-CSF-R transfectants with IgG-coated particles, there was a significant increase in phagocytosis in G-CSF stimulated cells, in which Syk tyrosine phosphorylation occurred, paralleled by enhancement of its tyrosine kinase activity. In the mutant transfectants, no significant increase in phagocytosis nor Syk tyrosine phosphorylation occurred after stimulation with G-CSF. We also demonstrated that tyrosine phosphorylation of two proteins of molecular weight corresponding to that of Src kinases Hck and Lyn occurs following G-CSF stimulation of cells expressing WT G-CSF-R, but that Hck is not phosphorylated in mutant G-CSF-R transfectants. The increase in phagocytosis following G-CSF stimulation cannot be attributed to a rapid de novo increase in expression of Fc receptors. G-CSF induced expression of FcRs only after prolonged stimulation. Our data provide evidence that the carboxyterminal region of G-CSF-R plays a role in the phagocytosis of IgG coated particles and that Syk tyrosine phosphorylation is involved. CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? This article has been cited by other articles: D. Metcalf Hematopoietic cytokines Blood, January 15, 2008; 111(2): 485 - 491. [Abstract] [Full Text] [PDF] C. H. Mermel, M. L. McLemore, F. Liu, S. Pereira, J. Woloszynek, C. A. Lowell, and D. C. Link Src family kinases are important negative regulators of G-CSF-dependent granulopoiesis Blood, October 15, 2006; 108(8): 2562 - 2568. [Abstract] [Full Text] [PDF] M. Ulanova, L. Puttagunta, M. Marcet-Palacios, M. Duszyk, U. Steinhoff, F. Duta, M.-K. Kim, Z. K. Indik, A. D. Schreiber, and A. D. Befus Syk tyrosine kinase participates in {beta}1-integrin signaling and inflammatory responses in airway epithelial cells Am J Physiol Lung Cell Mol Physiol, March 1, 2005; 288(3): L497 - L507. [Abstract] [Full Text] [PDF]

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