title: FAST is a BCL-X(L)-associated mitochondrial protein.
abstract: The TIA-1-interacting protein Fas-activated serine/threonine phosphoprotein (FAST) is a component of a signaling cascade that is initiated by ligation of the Fas receptor. Immunofluorescence microscopy using affinity-purified antibodies raised against recombinant FAST reveals that the endogenous protein associates with mitochondria. Subcellular fractionation confirms that FAST is a component of mitochondria. FAST is tethered to mitochondria by a lysine/arginine-rich domain at its carboxyl terminus that is structurally similar to the mitochondrial tethering motifs of monoamine oxidase B and cytochrome b5. At the mitochondrial membrane, FAST interacts with BCL-X(L). The BCL-X(L) binding domain maps to a BCL-2-homology-3 (BH3)-related domain that is distinct from the mitochondrial-tethering domain (MTD). Although interactions between FAST and BCL-X(L) require both the BH3-related domain and the MTD, the requirement for mitochondrial tethering can be conferred by a heterologous MTD. Our results suggest that FAST-BCL-X(L) interactions are likely to regulate mitochondrial metabolism during Fas-induced apoptosis.
authors.affiliation: Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Smith 652, One Jimmy Fund Way, Boston, MA 02115, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Nancy
authors.initials: N
authors.lastname: Kedersha
authors.forename: Samantha
authors.initials: S
authors.lastname: Chen
authors.forename: Natalie
authors.initials: N
authors.lastname: Gilks
authors.forename: Gene
authors.initials: G
authors.lastname: Lee
authors.forename: Paul
authors.initials: P
authors.lastname: Anderson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D002522:Chlorocebus aethiops; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013347:Subcellular Fractions / Q000201:enzymology; D014162:Transfection; D051020:bcl-X Protein
chemical_list: C494811:BCL2L1 protein, human; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D051020:bcl-X Protein; C095367:FASTK protein, human; D017346:Protein Serine-Threonine Kinases