Mak21p of Saccharomyces cerevisiae, a homolog of human CAATT-binding protein, is essential for 60 S ribosomal subunit biogenesis

J Biol Chem. 1998 Oct 30;273(44):28912-20. doi: 10.1074/jbc.273.44.28912.

Abstract

Mak21-1 mutants are unable to propagate M1 double-stranded RNA, a satellite of the L-A double-stranded RNA virus, encoding a secreted protein toxin lethal to yeast strains that do not carry M1. We cloned MAK21 using its map location and found that Mak21p is homologous to a human and mouse CAATT-binding protein and open reading frames in Schizosaccharomyces pombe and Caenorhabditis elegans. Although the human protein regulates Hsp70 production, Mak21p is essential for growth and necessary for 60 S ribosomal subunit biogenesis. mak21-1 mutants have decreased levels of L-A coat protein and L-A double-stranded RNA. Electroporation with reporter mRNAs shows that mak21-1 cells cannot optimally express mRNAs which, like L-A viral mRNA, lack 3'-poly(A) or 5'-cap structures but can normally express mRNA with both cap and poly(A). The virus propagation phenotype of mak21-1 is suppressed by ski2 or ski6 mutations, each of which derepresses translation of non-poly(A) mRNA.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Humans
  • Mice
  • Molecular Sequence Data
  • Neoplasm Proteins*
  • Open Reading Frames
  • Ribosomes / metabolism*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins*
  • Sequence Deletion
  • Sequence Homology, Amino Acid
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*

Substances

  • DNA-Binding Proteins
  • MAK21 protein, S cerevisiae
  • Neoplasm Proteins
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors