Through alternate splicing, this gene encodes two protein isoforms with similarity to subunits of the vacuolar ATPase V-ATPase but the encoded proteins seem to have different functions. V-ATPase is a multisubunit enzyme that mediates acidification of eukaryotic intracellular organelles. V-ATPase dependent organelle acidification is necessary for such intracellular processes as protein sorting, zymogen activation, and receptor-mediated endocytosis. V-ATPase is composed of a cytosolic V 1 domain and a transmembrane V 0 domain.

The two isoforms are:

  • Short isoform b, also named TIRC7 N-terminus truncated, lacks amino acid residues 1-216 of the long isoform.
  • Long isoform a, also named OC116.

TIRC7 is expressed in T-lymphocytes and is required for normal activation of T-cells. This option uses the start site of transcription, i.e. within the exon 5 of Variant 1, and then intron as part of its 5 UTR.

  • all known cases of intermediate autosomal osteopetrosis. Mutations in the TCIRG1 gene cause about 50 of cases of autosomal recessive osteopetrosis. Mutations
  • regulation of alpha3 subunit increasing damage to astrocytes. Osteopetrosis via TCIRG1 gene has a strong association with pre - senile dementia. Discovery and development
  • 2004 TCIRG1 - dependent recessive osteopetrosis: mutation analysis, functional identification of the splicing defects, and in vitro rescue by U 1 snRNA