title: The involvement of the 67 kDa laminin receptor-mediated modulation of cytoskeleton in the degranulation inhibition induced by epigallocatechin-3-O-gallate.
abstract: Recently, we have reported that (-)-epigallocatechin-3-O-gallate (EGCG) acts as an inhibitor of degranulation. However, the inhibitory mechanism for degranulation is still poorly understood. Here we show that suppression of exocytosis-related myosin II regulatory light chain phosphorylation and alteration of actin remodeling are involved in the inhibitory effect of EGCG on the calcium ionophore-induced degranulation from human basophilic KU812 cells. Surface plasmon resonance assay also revealed that EGCG binds to the cell surface, and the disruption of lipid rafts resulted in reduction of EGCG's ability. We have previously identified the raft-associated 67kDa laminin receptor (67LR) as an EGCG receptor on the cell surface. Treatment of the cells with anti-67LR antibody or RNA interference-mediated downregulation of 67LR expression abolished the effects of EGCG. These findings suggest that EGCG-induced inhibition of the degranulation includes the primary binding of EGCG to the cell surface 67LR and subsequent modulation of cytoskeleton.
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Fujimura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Umeda
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kiyohara
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Sunada
authors.forename: Koji
authors.initials: K
authors.lastname: Yamada
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tachibana
mesh_terms: D001491:Basophils / Q000187:drug effects; D000001:Calcimycin / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D015550:Cell Degranulation / Q000187:drug effects*; D045744:Cell Line, Tumor; D003599:Cytoskeleton / Q000187:drug effects*; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D021962:Membrane Microdomains / Q000502:physiology; D018994:Myosin Light Chains / Q000378:metabolism; D024462:Myosin Type II / Q000378:metabolism; D010766:Phosphorylation; D017474:Receptors, Laminin / Q000502:physiology*
chemical_list: D018994:Myosin Light Chains; D017474:Receptors, Laminin; D000001:Calcimycin; D002392:Catechin; C045651:epigallocatechin gallate; D024462:Myosin Type II