cigA, a light-inducible gene involved in vegetative growth in Mucor circinelloides is regulated by the carotenogenic repressor crgA.
A strategy based on the differential-display technique has been applied to identify and to isolate potential target genes controlled by crgA, a negative regulator of the light-inducible carotenogenesis in the fungus Mucor circinelloides. This approach resulted in the identification and cloning of the gene cigA, whose expression is repressed by the crgA gene. After a light pulse, there is an immediate though transient accumulation of transcripts of cigA gene. A similar result was obtained when mycelia were exposed to continuous illumination, suggesting the existence of a photoadaptation mechanism in M. circinelloides. The protein sequence deduced from the nucleotide sequence of cigA shows homology to the mouse and human GDP-fucose protein O-fucosyltransferases. Null cigA mutants were generated by gene replacement. Lack of cigA function does not affect carotenogenesis but provokes a slight reduction in vegetative growth that is independent of light. Introduction of wild-type cigA alleles into a cigA- strain restored the wild-type phenotype for vegetative growth. These results suggest that cigA is involved in vegetative growth and, moreover, that crgA controls cellular processes other than carotenogenesis.
Quiles-Rosillo
María D
MD
Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30071, Murcia, Spain.
Torres-Martínez
Santiago
S
Garre
Victoriano
V
D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D015139:Blotting, Southern; D002338:Carotenoids / Q000096:biosynthesis*; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D008027:Light; D008969:Molecular Sequence Data; D009089:Mucor / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects; D009154:Mutation; D010641:Phenotype; D012097:Repressor Proteins; D017386:Sequence Homology, Amino Acid
C404790:CRGA protein, Mucor circinelloides; D005656:Fungal Proteins; D012097:Repressor Proteins; D002338:Carotenoids