title: DNA delivery to mitochondria: sequence specificity and energy enhancement.
abstract: OBJECTIVE
  Mitochondria are competent for DNA uptake in vitro, a mechanism which may support delivery of therapeutic DNA to complement organelle DNA mutations. We document here key aspects of the DNA import process, so as to further lay the ground for mitochondrial transfection in intact cells.
  
  
  METHODS
  We developed DNA import assays with isolated mitochondria from different organisms, using DNA substrates of various sequences and sizes. Further import experiments investigated the possible role of ATP and protein phosphorylation in the uptake process. The fate of adenine nucleotides and the formation of phosphorylated proteins were analyzed.
  
  
  RESULTS
  We demonstrate that the efficiency of mitochondrial uptake depends on the sequence of the DNA to be translocated. The process becomes sequence-selective for large DNA substrates. Assays run with a natural mitochondrial plasmid identified sequence elements which promote organellar uptake. ATP enhances DNA import and allows tight integration of the exogenous DNA into mitochondrial nucleoids. ATP hydrolysis has to occur during the DNA uptake process and might trigger phosphorylation of co-factors.
  
  
  CONCLUSIONS
  Our data contribute critical information to optimize DNA delivery into mitochondria and open the prospect of targeting whole mitochondrial genomes or complex constructs into mammalian organelles in vitro and in vivo.
authors: Institut de Biologie Moléculaire des Plantes, CNRS and Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France.
authors: Noha
authors: N
authors: Ibrahim
authors: Hirokazu
authors: H
authors: Handa
authors: Anne
authors: A
authors: Cosset
authors: Milana
authors: M
authors: Koulintchenko
authors: Yuri
authors: Y
authors: Konstantinov
authors: Robert N
authors: RN
authors: Lightowlers
authors: André
authors: A
authors: Dietrich
authors: Frédérique
authors: F
authors: Weber-Lotfi
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D019184:Carmovirus / Q000235:genetics*; D004247:DNA / Q000032:analysis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016503:Drug Delivery Systems; D004353:Drug Evaluation, Preclinical; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006801:Humans; D008928:Mitochondria / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000032:analysis; D010766:Phosphorylation / Q000502:physiology; D021381:Protein Transport / Q000235:genetics; D003313:Zea mays / Q000235:genetics*
chemical_list: D010750:Phosphoproteins; D000255:Adenosine Triphosphate; D004247:DNA