Localization of plasma membrane Ca2+ pump mRNA and protein in human ameloblasts by in situ hybridization and immunohistochemistry.
The distribution of the plasma membrane Ca(2+)-pump (PMCA) proteins in human ameloblasts was examined immunohistochemically using monoclonal antibodies JA8 and 5F10. Further, the distribution of mRNA transcripts derived from two PMCA genes, PMCA-1 and PMCA-4 was examined using in situ hybridization. In rats, the PMCA-1 gene is purported to code for PMCA proteins with a role in maintaining the intracellular Ca2+ levels in nonepithelial cells. Other genes including the PMCA-4 gene may code for PMCA proteins characteristic of Ca2+ transporting epithelia. The present results show immunohistochemical staining in the Tomes processes and plasma membranes of human ameloblasts. Our studies also demonstrate a gradation of expression of the PMCA-1 and PMCA-4 mRNA transcripts which parallels the onset and progression of enamel mineralization. These studies suggest that PMCA proteins in human ameloblasts may function both in intracellular Ca2+ homeostasis and in regulating the vectorial Ca2+ influx into mineralizing enamel.
Borke
J L
JL
Department of Oral Biology-Physiology, Medical College of Georgia, School of Dentistry, Augusta 30912-1129, USA.
Zaki A el-M
Eisenmann
D R
DR
Mednieks
M I
MI
D000565:Ameloblasts / Q000201:enzymology* / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal; D000252:Calcium-Transporting ATPases / Q000032:analysis* / Q000235:genetics; D002462:Cell Membrane / Q000201:enzymology* / Q000378:metabolism; D004396:Coloring Agents; D003593:Cytoplasm / Q000201:enzymology; D018076:DNA, Complementary / Q000235:genetics; D004848:Epithelium / Q000201:enzymology; D005786:Gene Expression Regulation; D005796:Genes / Q000235:genetics; D006706:Homeostasis; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics; D051381:Rats; D014074:Tooth Calcification / Q000235:genetics; D014158:Transcription, Genetic
D000911:Antibodies, Monoclonal; D004396:Coloring Agents; D018076:DNA, Complementary; D012333:RNA, Messenger; D000252:Calcium-Transporting ATPases