title: The N-terminal helix of Bcl-xL targets mitochondria.
abstract: Anti- and pro-apoptotic Bcl-2 family members regulate the mitochondrial phase of apoptotic cell death. The mitochondrial targeting mechanisms of Bcl-2 family proteins are tightly regulated. Known outer mitochondrial membrane targeting sequences include the C-terminal tail and central helical hairpin. Bcl-xL also localizes to the inner mitochondrial membrane, but these targeting sequences are unknown. Here we investigate the possibility that the N-terminus of Bcl-xL also contains mitochondrial targeting information. Amino acid residues 1-28 of Bcl-xL fused to EGFP are sufficient to target mitochondria. Although positive charges and helical propensity are required for targeting, similar to import sequences the N-terminus is not sufficient for efficient mitochondrial import.
authors: W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, MD 21205, USA. mmcnall5@jhmi.edu
authors: Melanie A
authors: MA
authors: McNally
authors: Lucian
authors: L
authors: Soane
authors: Brian A
authors: BA
authors: Roelofs
authors: Adam L
authors: AL
authors: Hartman
authors: J Marie
authors: JM
authors: Hardwick
mesh_terms: D017209:Apoptosis; D019677:Artificial Gene Fusion; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006801:Humans; D008928:Mitochondria / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism; D021382:Protein Sorting Signals; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics; D051020:bcl-X Protein / Q000378:metabolism*
chemical_list: D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D051020:bcl-X Protein; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins