The P450 oxidoreductase, RedA, controls development beyond the mound stage in Dictyostelium discoideum.
BACKGROUND
NADPH-cytochrome-P450 oxidoreductase (CPR) is a ubiquitous enzyme that belongs to a family of diflavin oxidoreductases and is required for activity of the microsomal cytochrome-P450 monooxygenase system. CPR gene-disruption experiments have demonstrated that absence of this enzyme causes developmental defects both in mouse and insect.


RESULTS
Annotation of the sequenced genome of D. discoideum revealed the presence of three genes (redA, redB and redC) that encode putative members of the diflavin oxidoreductase protein family. redA transcripts are present during growth and early development but then decline, reaching undetectable levels after the mound stage. redB transcripts are present in the same levels during growth and development while redC expression was detected only in vegetative growing cells. We isolated a mutant strain of Dictyostelium discoideum following restriction enzyme-mediated integration (REMI) mutagenesis in which redA was disrupted. This mutant develops only to the mound stage and accumulates a bright yellow pigment. The mound-arrest phenotype is cell-autonomous suggesting that the defect occurs within the cells rather than in intercellular signaling.


CONCLUSIONS
The developmental arrest due to disruption of redA implicates CPR in the metabolism of compounds that control cell differentiation.
Gonzalez-Kristeller
Daniela C
DC
Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av, Prof, Lineu Prestes 748, 05508-000, São Paulo, Brasil. danig@iq.usp.br
Farage
Layla
L
Fiorini
Leonardo C
LC
Loomis
William F
WF
da Silva
Aline M
AM
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004023:Dictyostelium / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D018507:Gene Expression Regulation, Developmental; D017125:Genes, Protozoan; D009154:Mutation; D009251:NADPH-Ferrihemoprotein Reductase / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D016053:RNA, Protozoan / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment
D018076:DNA, Complementary; D016053:RNA, Protozoan; D009251:NADPH-Ferrihemoprotein Reductase