The effects of LAMP1 and LAMP3 on M180 amelogenin uptake, localization and amelogenin mRNA induction by amelogenin protein

Liming Xu, Hidemitsu Harada, Akiyoshi Taniguchi

Research output: Contribution to journalArticle

21 Citations (Scopus)


We previously demonstrated that the uptake of M180 amelogenin protein in dental epithelial cells (HAT-7) results in increased levels of amelogenin mRNA through enhanced mRNA stabilization. To determine the processes involved in the uptake of extracellular M180 amelogenin by cells and in amelogenin intracellular trafficking in the amelogenin protein-mediated amelogenin mRNA expression pathway, we investigated the effects of LAMP1 and LAMP3, which are candidate M180 amelogenin receptors, on M180 amelogenin uptake, localization and amelogenin mRNA induction by amelogenin protein, using anti-LAMP-1 and anti-LAMP-3 antibodies and siRNA analysis. The results indicate that LAMP3 blocking by anti-LAMP-3 decreases M180 amelogenin uptake, but does not affect amelogenin mRNA induction by amelogenin protein, suggesting that LAMP3 is related to amelogenin degradation. Down-regulation by siRNA of LAMP1, which is the receptor for small amelogenin protein (LRAP), does not affect M180 amelogenin uptake, localization or amelogenin mRNA induction by amelogenin protein. Thus, while LAMP1 is the specific receptor for LRAP, it is not a receptor for M180 amelogenin. These findings will aid further research into the understanding of M180 amelogenin function and expression.

Original languageEnglish
Pages (from-to)531-537
Number of pages7
JournalJournal of Biochemistry
Issue number4
Publication statusPublished - 2008 Oct
Externally publishedYes



  • Ameloblast
  • Amelogenin
  • LAMP1
  • LAMP3
  • Tooth development

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

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