RRC ID 42836
Author Nagasawa M, Nakagawa Y, Tanaka S, Kojima I.
Title Chemotactic peptide fMetLeuPhe induces translocation of the TRPV2 channel in macrophages.
Journal J Cell Physiol
Abstract The present study was conducted to characterize the regulation and function of TRPV2 in macrophages. Among six members of the TRPV family channels, only the expression of TRPV2 was detected in macrophages. We then determined localization of TRPV2 using TtT/M87 macrophages transfected with TRPV2-EGFP. In serum-free condition, most of the TRPV2 signal was located in the cytoplasm and colocalized with the endoplasmic reticulum marker. Treatment with serum induced translocation of some of the TRPV2-EGFP to the plasma membrane. Serum-induced translocation was blocked by transfection of short-form TRPV2 (s-TRPV2) lacking a pore-forming region and the sixth transmembrane domain. Addition of a chemotactic peptide formyl Met-Leu-Phe (fMLP) also induced translocation of TRPV2-EGFP to the plasma membrane. The fMLP-induced translocation was blocked by an inhibitor of PI 3-kinase, LY294002, and pertussis toxin. Whole-cell patch clamp analysis showed a Cs+ current in the TtT/M87 cell, which was blocked by an addition of ruthenium red and transfection of either s-TRPV2 or siRNA for TRPV2. fMLP increased the Cs+ current. fMLP induced a rapid and sustained elevation of cytoplasmic Ca2+ ([Ca2+]C), the sustained phase of which was abolished by removal of extracellular calcium. The sustained elevation of [Ca2+]C was also blocked by ruthenium red, and transfection of either s-TRPV2 or siRNA. Finally, fMLP-induced migration of macrophage was blocked by ruthenium red or transfection of s-TRPV2. These results suggest that fMLP induces translocation of TRPV2 from intracellular compartment to the plasma membrane, and this translocation is critical for fMLP-induced calcium entry.
Volume 210(3)
Pages 692-702
Published 2007-3
DOI 10.1002/jcp.20883
PMID 17154364
MeSH Amino Acid Sequence Animals Calcium / metabolism Calcium Channels / analysis Calcium Channels / genetics Calcium Channels / metabolism* Cell Line Cell Line, Tumor Cell Membrane / metabolism Chemotactic Factors / pharmacology* Chromones / pharmacology Enzyme Inhibitors / pharmacology Gene Expression Regulation / physiology Humans Macrophages / cytology Macrophages / metabolism* Macrophages / pathology Mice Molecular Sequence Data Morpholines / pharmacology N-Formylmethionine Leucyl-Phenylalanine / pharmacology* Pertussis Toxin / pharmacology Phosphoinositide-3 Kinase Inhibitors Protein Transport / drug effects RNA, Messenger / genetics RNA, Messenger / metabolism Rats TRPV Cation Channels / analysis TRPV Cation Channels / genetics TRPV Cation Channels / metabolism* Thapsigargin / pharmacology
IF 4.522
Times Cited 80
Human and Animal Cells