The targeting information of the mitochondrial outer membrane isoform of cytochrome b5 is contained within the carboxyl-terminal region.
Two isoforms of mammalian cytochrome b5, which have homologous cytosolic amino-terminal catalytic domains, are located one on endoplasmic reticulum (ER b5) the other on mitochondrial outer membranes (OM b5). A cDNA coding for the previously unknown carboxyl-terminal domain of OM b5 was cloned and a chimera between the catalytic domain of ER b5 and the carboxyl-terminal region of OM b5 was expressed in cultured mammalian cells. The chimera localized to mitochondria, indicating that the carboxyl-terminal 43 amino acids of OM b5 contain sufficient information to target the catalytic domain of ER b5 to the mitochondrial outer membrane.
De Silvestris
M
M
C.N.R. Center for Cytopharmacology, Milano, Italy.
D'Arrigo
A
A
Borgese
N
N
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D015786:Cytochromes b5 / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D017931:DNA Primers; D004721:Endoplasmic Reticulum / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism*; D007668:Kidney; D008099:Liver / Q000378:metabolism; D008322:Mammals; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D017931:DNA Primers; D011993:Recombinant Fusion Proteins; D015786:Cytochromes b5