Molecular cloning, sequencing, chromosomal localization and expression of mouse p21 (Waf1)

Oncogene. 1994 Oct;9(10):3017-20.


The recent discovery that expression of Waf1 (p21), an inhibitor of cyclin-dependent kinases, is induced by the tumor suppressor p53 provides an important linkage between growth suppression and the cell cycle. We report here the cloning and sequencing of a mouse p21 cDNA that contains the entire coding region. Hybridization of the mouse p21 probe in Southern blot analyses confirms that p21 is a single-copy gene and that the corresponding locus, Waf1, lies proximal to H-2 on mouse chromosome 17. In northern analyses, the expression of p21 is found in most normal mouse tissues, but a surprising lack of correlation is found between mRNA levels of p21 and p53. In order to determine which regions of p21 are most evolutionarily conserved, we have compared the cDNA sequences for the entire p21 coding region in 13 different mouse strains or species and the human p21 sequence. We conclude that two regions (corresponding to human codons 21-60 and 130-164) are strongly conserved in p21 and that these regions may represent domains that are especially critical to a functional p21 protein.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Chromosome Mapping*
  • Cloning, Molecular
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins / genetics*
  • DNA
  • Humans
  • Mice
  • Mice, Inbred Strains
  • Molecular Sequence Data
  • Protein Kinase Inhibitors*
  • Sequence Homology, Amino Acid
  • Species Specificity


  • CDKN1A protein, human
  • Cdkn1a protein, mouse
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins
  • Protein Kinase Inhibitors
  • DNA

Associated data

  • GENBANK/U09507