title: Expression of prohibitins on the surface of activated T cells.
abstract: Prohibitins (prohibitin-1 and -2) comprise a family of highly conserved proteins that are mainly localized to mitochondria. Recent studies showed that prohibitins are up-regulated upon T cell activation and play an essential role in maintaining mitochondrial homeostasis. In the present study, we found that a considerable proportion of prohibitin-1 and -2 induced in response to T cell activation was expressed on the surface of activated T cells. When mouse and human T cells were stimulated with PMA and ionomycin, prohibitins expressed on the cell surface were increased significantly, peaking at 48 h after stimulation. Stimulation of mouse T cells with anti-CD3 and anti-CD28 antibodies also remarkably induced the cell surface expression of prohibitins. Their expression on the cell surface was also detected in T cell leukemia cells such as Jurkat cells. In Jurkat cells, prohibitin-1 and -2 were co-localized with CD3 on the cell surface, and anti-CD3 antibody-induced signaling, the MAP kinase cascade, was inhibited on treatment with protein A magnetic beads co-conjugated with anti-CD3 antibody and anti-prohibitin-1 or anti-prohibitin-2 antibody. These results suggest that prohibitins expressed on the surface of activated T cells are involved in the T cell receptor-mediated signaling cascade.
authors.affiliation: Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kitaku, Kyoto 603-8555, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Yurugi
authors.forename: Shuhei
authors.initials: S
authors.lastname: Tanida
authors.forename: Akiko
authors.initials: A
authors.lastname: Ishida
authors.forename: Kaoru
authors.initials: K
authors.lastname: Akita
authors.forename: Munetoyo
authors.initials: M
authors.lastname: Toda
authors.forename: Mizue
authors.initials: M
authors.lastname: Inoue
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakada
mesh_terms: D000818:Animals; D000906:Antibodies; D002462:Cell Membrane / Q000276:immunology*; D005260:Female; D006801:Humans; D019169:Jurkat Cells; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D000091402:Prohibitins; D012097:Repressor Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000906:Antibodies; D000091402:Prohibitins; D012097:Repressor Proteins