title: Cross-talk between tetraspanin CD9 and transmembrane adaptor protein non-T cell activation linker (NTAL) in mast cell activation and chemotaxis.
abstract: Chemotaxis, a process leading to movement of cells toward increasing concentrations of chemoattractants, is essential, among others, for recruitment of mast cells within target tissues where they play an important role in innate and adaptive immunity. Chemotaxis is driven by chemoattractants, produced by various cell types, as well as by intrinsic cellular regulators, which are poorly understood. In this study we prepared a new mAb specific for the tetraspanin CD9. Binding of the antibody to bone marrow-derived mast cells triggered activation events that included cell degranulation, Ca(2+) response, dephosphorylation of ezrin/radixin/moesin (ERM) family proteins, and potent tyrosine phosphorylation of the non-T cell activation linker (NTAL) but only weak phosphorylation of the linker for activation of T cells (LAT). Phosphorylation of the NTAL was observed with whole antibody but not with its F(ab)(2) or Fab fragments. This indicated involvement of the Fcγ receptors. As documented by electron microscopy of isolated plasma membrane sheets, CD9 colocalized with the high-affinity IgE receptor (FcεRI) and NTAL but not with LAT. Further tests showed that both anti-CD9 antibody and its F(ab)(2) fragment inhibited mast cell chemotaxis toward antigen. Experiments with bone marrow-derived mast cells deficient in NTAL and/or LAT revealed different roles of these two adaptors in antigen-driven chemotaxis. The combined data indicate that chemotaxis toward antigen is controlled in mast cells by a cross-talk among FcεRI, tetraspanin CD9, transmembrane adaptor proteins NTAL and LAT, and cytoskeleton-regulatory proteins of the ERM family.
authors: Department of Signal Transduction, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ 14220 Prague, Czech Republic.
authors: Ivana
authors: I
authors: Hálová
authors: Department of Signal Transduction, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ 14220 Prague, Czech Republic.
authors: Lubica
authors: L
authors: Dráberová
authors: Department of Signal Transduction, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ 14220 Prague, Czech Republic.
authors: Monika
authors: M
authors: Bambousková
authors: Department of Signal Transduction, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ 14220 Prague, Czech Republic.
authors: Martin
authors: M
authors: Machyna
authors: Department of Signal Transduction, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ 14220 Prague, Czech Republic.
authors: Lucie
authors: L
authors: Stegurová
authors: Department of Signal Transduction, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ 14220 Prague, Czech Republic.
authors: Daniel
authors: D
authors: Smrž
authors: Department of Signal Transduction, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, CZ 14220 Prague, Czech Republic. Electronic address: draberpe@img.cas.cz.
authors: Petr
authors: P
authors: Dráber
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D027182:Amino Acid Transport System y+ / Q000378:metabolism*; D000818:Animals; D000941:Antigens / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002633:Chemotaxis; D003599:Cytoskeleton / Q000378:metabolism; D027301:Fusion Regulatory Protein 1, Light Chains / Q000378:metabolism*; D005966:Glucuronidase / Q000378:metabolism; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry; D008407:Mast Cells / Q000166:cytology*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D051381:Rats; D017208:Rats, Wistar; D017455:Receptors, IgE / Q000378:metabolism*; D060245:Tetraspanin 29 / Q000502:physiology*; D014443:Tyrosine / Q000737:chemistry
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D027182:Amino Acid Transport System y+; D000941:Antigens; D027301:Fusion Regulatory Protein 1, Light Chains; D007140:Immunoglobulin Fab Fragments; C491734:Lat protein, mouse; C491733:Lat protein, rat; D008565:Membrane Proteins; D010750:Phosphoproteins; D017455:Receptors, IgE; C518286:SLC7A8 protein, mouse; C486582:Slc7a8 protein, rat; D060245:Tetraspanin 29; D014443:Tyrosine; D005966:Glucuronidase; D002118:Calcium