title: Isolation and analysis of the Neurospora crassa Cyt-21 gene. A nuclear gene encoding a mitochondrial ribosomal protein.
abstract: The Neurospora crassa nuclear mutant cyt-21-1 (originally 297-24; Pittenger, T.H., and West, D.J. (1979) Genetics 93, 539-555) has a defect leading to gross deficiency of mitochondrial small ribosomal subunits. Here, we have cloned the cyt-21+ gene from a N. crassa genomic library, using the sib selection procedure (Akins, R. A., and Lambowitz, A. M. (1985) Mol. Cell Biol. 5, 2272-2278). The genomic clone contains a short split gene encoding a basic protein of 107 amino acid residues. This protein shows strong homology to Escherichia coli ribosomal protein S-16. Comparison of mutant and wild-type mitochondrial ribosomal proteins (Kuiper, M. T. R., Holtrop, M., Vennema, H., Lambowitz, A. M., and de Vries, H. (1988) J. Biol. Chem. 263, 2848-2852) indicates that the cyt-21 gene encodes N. crassa mitochondrial ribosomal protein S-24. The expression of the cyt-21+ gene is regulated such that the level of the putative cyt-21+ mRNA is increased about 5-fold when mitochondrial protein synthesis is inhibited. We suggest that this reflects part of a general mechanism for coordinately activating Neurospora nuclear genes that encode mitochondrial constituents in response to impaired mitochondrial function. This is the first report of the cloning and characterization of a mitochondrial ribosomal protein gene from N. crassa.
authors.affiliation: Laboratory of Physiological Chemistry, State University Groningen, The Netherlands.
authors.forename: M T
authors.initials: MT
authors.lastname: Kuiper
authors.forename: R A
authors.initials: RA
authors.lastname: Akins
authors.forename: M
authors.initials: M
authors.lastname: Holtrop
authors.forename: H
authors.initials: H
authors.lastname: de Vries
authors.forename: A M
authors.initials: AM
authors.lastname: Lambowitz
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004262:DNA Restriction Enzymes / Q000378:metabolism; D005800:Genes, Fungal; D008928:Mitochondria / Q000032:analysis*; D008969:Molecular Sequence Data; D009154:Mutation; D009491:Neurospora / Q000235:genetics*; D009492:Neurospora crassa / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D012269:Ribosomal Proteins / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D012269:Ribosomal Proteins; D004262:DNA Restriction Enzymes