High impact information on mt-Cytb

• We have isolated a complementary DNA, Dcytb (for duodenal cytochrome b), which encoded a putative plasma membrane di-heme protein in mouse duodenal mucosa [1].
• We have reproduced the combined complex I+III defect in mouse and human cultured cell models harboring cytochrome b mutations [2].
• Expression of cytochrome b was also inhibited in mouse NIH 3T3 cells treated with interferon alpha/beta and in human Daudi lymphoblastoid cells treated with interferon alpha [3].
• The mitochondrial gene for the cytochrome b of Complex III has been cloned from a mouse L-cell mutant with increased resistance to 2-n-heptyl-4-hydroxyquinoline-N-oxide and other inhibitors which block reactions at the b562 heme group [4].
• At the amino acid level, this mutation results in the substitution of an aspartic acid residue for a conserved glycine at position 231 of cytochrome b [4].

Biological context of mt-Cytb

• Genes Cytb and Nd4 also produced the correct tree in most tree-building algorithms when amino acid sequence data were used [5].
• The nature of RNA coded by the only light-strand (L-strand) open-reading frame unidentified reading frame 6 (URF6) was studied by using a variety of single- and double-strand DNA subclones derived from the 3.6-kilobase (kb) cytochrome b (cyt b)-URF5 coding region of the mouse mitochondrial genome [6].
• Molecular phylogeny and taxonomy of wood mice (genus Apodemus Kaup, 1829) based on complete mtDNA cytochrome b sequences, with emphasis on Chinese species [7].
• Nucleotide sequence data from the mitochondrial cytochrome b gene were used to evaluate the phylogenetic relationships among mouse opossum species of the genus Thylamys [8].
• A survey of 21 microsatellite DNA loci and 1380 base pairs from two mitochondrial DNA (mtDNA) regions (control region and cytochrome b) revealed that each Z. hudsonius subspecies is genetically distinct [9].

Anatomical context of mt-Cytb

• Human phagocyte flavocytochrome b558 (Cytb) is a heterodimeric integral membrane protein that serves as the electron transferase of the beta-nicotinamide adenine dinucleotidephosphate, reduced (NADPH)-oxidase, an enzyme complex important in the host defense function of phagocytic cells [10].
• We conclude that mAb CL5 is a useful probe for detection of full length and possibly truncated N-terminal fragments of gp91phox from membranes of Cytb-producing cells [10].

Associations of mt-Cytb with chemical compounds

• Based upon current models for the secondary structure of cytochrome b, the altered amino acid lies in close proximity to one of the invariant histidine residues involved in binding the heme groups [4].
• Resistance mutations reveal the atovaquone-binding domain of cytochrome b in malaria parasites [11].
• The general conclusion from these experiments is that when an inhibitor binds to a quinone redox site of the cytochrome b protein, it produces local conformational changes that, in turn, are transmitted to distal regions of the protein [12].
• The redox state of NAD(P)+, determined in steady-state conditions, changed to a more reduced level, and the redox states of ubiquinone, cytochrome b, cytochromes c + c1 and cytochromes a + a3 changed to a more oxidized level [13].
• Increase of cytochrome b mRNA by bis(2-hydroxyethyl) trisulfide in J774A.1 cells [14].

Other interactions of mt-Cytb

• We sequenced mitochondrial (cytochrome b, 12S rRNA) and nuclear (IRBP, RAG1) genes for 17 species of the Old World murine genus Mus, drawn primarily from the Eurasian subgenus Mus [15].
• We extended the previous sampling of mitochondrial cytochrome b sequence and added information from the Y-linked Sry gene and ribosomal RNA gene surveys [16].
• This paper investigates the usefulness of two mitochondrial genes (16S rRNA and cytochrome b) to solve taxonomical difficulties within the genus Hylomyscus and to infer its evolutionary history [17].

Analytical, diagnostic and therapeutic context of mt-Cytb

• Analysis of proteins synthesized in the presence of emetine, a specific inhibitor of cytoplasmic translation, showed that the synthesis of several mitochondrial translation products, including cytochrome b, was reduced after treatment with interferon [3].
• The mouse islets exposed to SZ, NMU and MMS showed on day 6 a 30-40% decrease in the content of the mitochondrial DNA encoded cytochrome b mRNA and a 60-70% decrease in total mitochondrial DNA, as evaluated by dot and Southern blot analysis [18].
• In fact, Northern blot analysis showed that cytochrome b mRNA in J774A.1 cells was increased by BS-1 [14].
• The sequence analysis revealed that the gene was identical to mouse mitochondrial cytochrome b [14].

References