STIM1 and SLC24A4 Are Critical for Enamel Maturation

J Dent Res. 2014 Jul;93(7 Suppl):94S-100S. doi: 10.1177/0022034514527971. Epub 2014 Mar 12.


Dental enamel formation depends upon the transcellular transport of Ca(2+) by ameloblasts, but little is known about the molecular mechanism, or even if the same process is operative during the secretory and maturation stages of amelogenesis. Identifying mutations in genes involved in Ca(2+) homeostasis that cause inherited enamel defects can provide insights into the molecular participants and potential mechanisms of Ca(2+) handling by ameloblasts. Stromal Interaction Molecule 1 (STIM1) is an ER transmembrane protein that activates membrane-specific Ca(2+) influx in response to the depletion of ER Ca(2+) stores. Solute carrier family 24, member 4 (SLC24A4), is a Na(+)/K(+)/Ca(2+) transporter that exchanges intracellular Ca(2+) and K(+) for extracellular Na(+). We identified a proband with syndromic hypomaturation enamel defects caused by a homozygous C to T transition (g.232598C>T c.1276C>T p.Arg426Cys) in STIM1, and a proband with isolated hypomaturation enamel defects caused by a homozygous C to T transition (g.124552C>T; c.437C>T; p.Ala146Val) in SLC24A4. Immunohistochemistry of developing mouse molars and incisors showed positive STIM1 and SLC24A4 signal specifically in maturation-stage ameloblasts. We conclude that enamel maturation is dependent upon STIM1 and SLC24A4 function, and that there are important differences in the Ca(2+) transcellular transport systems used by secretory- and maturation-stage ameloblasts.

Keywords: amelogenesis imperfecta; calcium; inherited diseases; mutations; tooth.

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural

MeSH terms

  • Alanine / genetics
  • Ameloblasts / physiology
  • Amelogenesis / genetics
  • Amelogenesis / physiology*
  • Animals
  • Antiporters / genetics
  • Antiporters / physiology*
  • Arginine / genetics
  • Calcium Signaling / physiology
  • Child
  • Child, Preschool
  • Consanguinity
  • Cysteine / genetics
  • Cytosine
  • Dental Enamel Hypoplasia / genetics
  • Female
  • Genetic Variation / genetics
  • Homozygote
  • Humans
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Mice
  • Mutation, Missense / genetics
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / physiology*
  • Pedigree
  • Stromal Interaction Molecule 1
  • Thymine
  • Valine / genetics


  • Antiporters
  • Membrane Proteins
  • Neoplasm Proteins
  • SLC24A4 protein, human
  • STIM1 protein, human
  • Stromal Interaction Molecule 1
  • Cytosine
  • Arginine
  • Valine
  • Cysteine
  • Alanine
  • Thymine