Overexpression of the crgA gene abolishes light requirement for carotenoid biosynthesis in Mucor circinelloides.
This work describes the isolation and characterization of crgA, a Mucor circinelloides gene, which has a dominant-positive effect on light-regulated carotenogenesis. The crgA gene was originally identified in a transformation experiment as a 3'-truncated open reading frame which caused carotenoid overaccumulation in the dark. The complete cloning and sequencing of crgA revealed that its putative product presented several recognizable structural domains: a RING-finger zinc binding domain near the N-terminus, a putative nuclear localization signal, two stretches of acidic amino acids, glutamine-rich regions and a putative isoprenylation motif. The expression of exogenous copies of the complete crgA gene or two different 3'-truncated versions, produced a similar dominant-positive effect on the light-inducible carotenogenesis of M. circinelloides. The presence of these exogenous sequences also caused a missregulation of the endogenous crgA gene, resulting in its overexpression. Collectively, these observations suggest that crgA is involved in the regulation of carotenoid biosynthesis by light.
Navarro
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Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Spain.
Ruiz-Pérez
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VL
Torres-Martínez
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S
D000595:Amino Acid Sequence; D001483:Base Sequence; D002338:Carotenoids / Q000096:biosynthesis*; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics*; D015870:Gene Expression; D005800:Genes, Fungal; D008027:Light; D008969:Molecular Sequence Data; D009089:Mucor / Q000235:genetics* / Q000378:metabolism* / Q000528:radiation effects; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014170:Transformation, Genetic
C404790:CRGA protein, Mucor circinelloides; D004271:DNA, Fungal; D005656:Fungal Proteins; D002338:Carotenoids