title: Constitutive association of the proapoptotic protein Bim with Bcl-2-related proteins on mitochondria in T cells.
abstract: Apoptosis in activated T cells in vivo requires the proapoptotic Bcl-2 family member Bim. We show here that, despite its ability to bind LC8, a component of the microtubule dynein motor complex, most of the Bim in both healthy and apoptotic T cells is associated with mitochondria, not microtubules. In healthy resting T cells Bim is bound to the antiapoptotic proteins Bcl-2 and Bcl-x(L). In activated T cells, levels of Bcl-2 fall, and Bim is associated more with Bcl-x(L) and less with Bcl-2. Our results indicate that, in T cells, Bim function is regulated by interaction with Bcl-2 family members on mitochondria rather than by sequestration to the microtubules.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Zhu
authors.forename: Bradley J
authors.initials: BJ
authors.lastname: Swanson
authors.forename: Michael
authors.initials: M
authors.lastname: Wang
authors.forename: David A
authors.initials: DA
authors.lastname: Hildeman
authors.forename: Brian C
authors.initials: BC
authors.lastname: Schaefer
authors.forename: Xinqi
authors.initials: X
authors.lastname: Liu
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Suzuki
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Mihara
authors.forename: John
authors.initials: J
authors.lastname: Kappler
authors.forename: Philippa
authors.initials: P
authors.lastname: Marrack
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D009154:Mutation; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism*
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2