The CHL 1 (CTF 1) gene product of Saccharomyces cerevisiae is important for chromosome transmission and normal cell cycle progression in G2/M

EMBO J. 1990 Dec;9(13):4347-58.


We have analyzed the CTF1 gene, identified in a screen for mutants with decreased chromosome transmission fidelity and shown to correspond to the previously identified chl1 mutation. Chl1 null mutants exhibited a 200-fold increase in the rate of chromosome III missegregation per cell division, and near wild-type rates of marker homozygosis on this chromosome by mitotic recombination. Analysis of the segregation of a marker chromosome indicated that sister chromatid loss (1:0 segregation) and sister chromatid non-disjunction (2:0 segregation) contributed equally to chromosome missegregation. A genomic clone of CHL1 was isolated and used to map its physical position on chromosome XVI. Nucleotide sequence analysis of CHL1 revealed a 2.6 kb open reading frame with a 99 kd predicted protein sequence that contained two PEST sequences and was 23% identical to the coding region of a nucleotide excision repair gene, RAD3. Domains of homology between these two predicted protein sequences included a helix-turn-helix motif and an ATP binding site containing a helicase consensus. Mutants lacking the CHL1 gene product are viable and display two striking, and perhaps interrelated, phenotypes: extreme chromosome instability and a delay in cell cycle progression in G2/M. This delay is independent of the cell cycle checkpoint that requires the function of the RAD9 gene.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Base Sequence
  • Cell Cycle*
  • Chromosomal Proteins, Non-Histone*
  • Chromosome Mapping
  • Chromosomes, Fungal / metabolism*
  • Cloning, Molecular
  • DNA, Fungal / chemistry
  • Fungal Proteins / genetics*
  • Genes, Fungal*
  • Genetic Markers
  • Molecular Sequence Data
  • Mutation
  • Phenotype
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Nucleic Acid
  • Spores, Fungal / analysis


  • CHL1 protein, S cerevisiae
  • Chromosomal Proteins, Non-Histone
  • DNA, Fungal
  • Fungal Proteins
  • Genetic Markers
  • Saccharomyces cerevisiae Proteins