Cementum attachment protein/protein-tyrosine phosphotase-like member A is not expressed in teeth

Int J Mol Med. 2009 Feb;23(2):293-6.


Cementum is a highly specialized connective tissue that covers tooth roots. The only cementum-specific protein described to date is the cementum attachment protein (CAP). A putative sequence for CAP was established from a cDNA clone isolated from a human cementifying fibroma cDNA library. This sequence overlaps with a phosphatase-like protein in muscle termed the protein-tyrosine phosphatase-like member A (PTPLA). To clarify the nature of CAP/PTPLA, we cloned the homologous rat protein and determined its sequence. The rat protein shared 94% sequence identity with the human protein. On Northern blots containing RNA from various rat tissues of different developmental stages, the cDNA hybridized to an mRNA expressed in heart and skeletal muscle but not in teeth. These results were confirmed by real-time PCR. Thus, the sequence deposited in public databanks under the name 'cementum attachment protein' does not represent genuine CAP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Adhesion Molecules / genetics*
  • Cell Adhesion Molecules / metabolism
  • Humans
  • Models, Genetic
  • Molecular Sequence Data
  • Protein Tyrosine Phosphatases / genetics*
  • Protein Tyrosine Phosphatases / metabolism
  • Rats
  • Sequence Alignment
  • Tooth / metabolism*


  • Cell Adhesion Molecules
  • Hacd1 protein, rat
  • Protein Tyrosine Phosphatases