Histone H1 Is required for proper regulation of pyruvate decarboxylase gene expression in Neurospora crassa.
We show that Neurospora crassa has a single histone H1 gene, hH1, which encodes a typical linker histone with highly basic N- and C-terminal tails and a central globular domain. A green fluorescent protein-tagged histone H1 chimeric protein was localized exclusively to nuclei. Mutation of hH1 by repeat-induced point mutation (RIP) did not result in detectable defects in morphology, DNA methylation, mutagen sensitivity, DNA repair, fertility, RIP, chromosome pairing, or chromosome segregation. Nevertheless, hH1 mutants had mycelial elongation rates that were lower than normal on all tested carbon sources. This slow linear growth phenotype, however, was less evident on medium containing ethanol. The pyruvate decarboxylase gene, cfp, was abnormally derepressed in hH1 mutants on ethanol-containing medium. This derepression was also found when an ectopically integrated fusion of the cfp gene promoter to the reporter gene hph was analyzed. Thus, Neurospora histone H1 is required for the proper regulation of cfp, a gene with a key role in the respiratory-fermentative pathway.
Folco
H Diego
HD
Instituto de Investigación Médica Mercedes y Martín Ferreyra, Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, 5016 Córdoba, Argentina.
Freitag
Michael
M
Ramón
Ana
A
Temporini
Esteban D
ED
Alvarez
María E
ME
García
Irene
I
Scazzocchio
Claudio
C
Selker
Eric U
EU
Rosa
Alberto L
AL
D000595:Amino Acid Sequence / Q000235:genetics; D001483:Base Sequence / Q000235:genetics; D019069:Cell Respiration / Q000187:drug effects / Q000235:genetics*; D048429:Cell Size / Q000235:genetics; D020090:Chromosome Segregation / Q000235:genetics; D019175:DNA Methylation; D004260:DNA Repair / Q000235:genetics; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D000431:Ethanol / Q000494:pharmacology; D015966:Gene Expression Regulation, Fungal / Q000235:genetics*; D006657:Histones / Q000235:genetics*; D008969:Molecular Sequence Data; D009153:Mutagens / Q000494:pharmacology; D009492:Neurospora crassa / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D017354:Point Mutation / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D011767:Pyruvate Decarboxylase / Q000096:biosynthesis* / Q000235:genetics
D006657:Histones; D009153:Mutagens; D000431:Ethanol; D011767:Pyruvate Decarboxylase