Retinoblastoma protein enhances the fidelity of chromosome segregation mediated by hsHec1p

Mol Cell Biol. 2000 May;20(10):3529-37. doi: 10.1128/MCB.20.10.3529-3537.2000.


Retinoblastoma protein (Rb) plays important roles in cell cycle progression and cellular differentiation. It may also participate in M phase events, although heretofore only circumstantial evidence has suggested such involvement. Here we show that Rb interacts, through an IxCxE motif and specifically during G(2)/M phase, with hsHec1p, a protein essential for proper chromosome segregation. The interaction between Rb and hsHec1p was reconstituted in a yeast strain in which human hsHEC1 rescues the null mutation of scHEC1. Expression of Rb reduced chromosome segregation errors fivefold in yeast cells sustained by a temperature-sensitive (ts) hshec1-113 allele and enhanced the ability of wild-type hsHec1p to suppress lethality caused by a ts smc1 mutation. The interaction between Hec1p and Smc1p was important for the specific DNA-binding activity of Smc1p. Expression of Rb restored part of the inactivated function of hshec1-113p and thereby increased the DNA-binding activity of Smc1p. Rb thus increased the fidelity of chromosome segregation mediated by hsHec1p in a heterologous yeast system.

Publication types

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

MeSH terms

  • Amino Acid Motifs
  • Binding Sites
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Chromosomal Proteins, Non-Histone*
  • Chromosome Segregation*
  • Cytoskeletal Proteins
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • G2 Phase
  • Genes, Lethal
  • Mitosis
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Protein Binding
  • Recombinant Proteins / metabolism
  • Retinoblastoma Protein / genetics
  • Retinoblastoma Protein / metabolism*
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / genetics
  • Suppression, Genetic


  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • Cytoskeletal Proteins
  • DNA-Binding Proteins
  • Fungal Proteins
  • NDC80 protein, human
  • Nuclear Proteins
  • Recombinant Proteins
  • Retinoblastoma Protein
  • structural maintenance of chromosome protein 1