The erg-3 (sterol delta14,15-reductase) gene of Neurospora crassa: generation of null mutants by repeat-induced point mutation and complementation by proteins chimeric for human lamin B receptor sequences.
Null mutations were generated in the erg-3 gene of Neurospora crassa by repeat-induced point mutation (RIP). The mutants were viable, lacked ergosterol, were resistant to the steroidal glycoside alpha-tomatine and were sensitive to the phytoalexins pisatin and biochanin A. RIP was frequently associated with silencing of the hph gene located adjacent to the duplicated erg-3 sequence. The silencing of hph was reversible in the two cases examined and appeared to be due to the spread of cytosine methylation associated with RIP. The erg-3 mutant could be complemented by transformation with recombinant genes that encode proteins chimeric for amino acid sequences from the transmembrane (TM) domain of human lamin B receptor (LBR). This indicates that the LBR TM domain possesses delta14,15-reductase activity.
Prakash
A
A
Sengupta
Saswati
S
Aparna
K
K
Kasbekar
Durgadas P
DP
D000595:Amino Acid Sequence; D003470:Culture Media; D005816:Genetic Complementation Test; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D009492:Neurospora crassa / Q000201:enzymology / Q000235:genetics*; D010088:Oxidoreductases / Q000235:genetics*; D017354:Point Mutation; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics* / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D013261:Sterols / Q000032:analysis; D000097682:Lamin B Receptor
D003470:Culture Media; D008565:Membrane Proteins; D010088:Oxidoreductases; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D013261:Sterols; D000097682:Lamin B Receptor; C022672:delta(14)-sterol reductase