The 1,25D3-MARRS protein: contribution to steroid stimulated calcium uptake in chicks and rats.
There are currently two main candidates for the membrane receptor for 1,25(OH)2D3: the 1,25D3-MARRS protein/ERp57; and the classical VDR. The 1,25D3-MARRS protein is essential for hormone-stimulated phosphate and calcium uptake in chick intestinal cells, whereas the VDR is not. The 1,25D3-MARRS protein also shows a high degree of correlation with growth periods in which bone is rapidly formed, whereas the VDR does not. However, in rat enterocytes, both the 1,25D3-MARRS protein and the VDR play a role in the rapid, steroid-mediated uptake of phosphate or calcium. Therefore, the theory that alternate binding sites on the VDR for various analogs account for all membrane-initiated phenomena, is incorrect.
Nemere
Ilka
I
Department of Nutrition and Food Sciences, Center for Integrated BioSystems, Utah State University, Logan, UT 84322 8700, USA. Nemere@cc.usu.edu
D000818:Animals; D001665:Binding Sites; D001842:Bone and Bones / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry*; D002462:Cell Membrane / Q000378:metabolism; D002645:Chickens; D004912:Erythrocytes / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism / Q000502:physiology*; D007413:Intestinal Mucosa / Q000378:metabolism; D007535:Isomerases / Q000378:metabolism / Q000502:physiology*; D019704:Protein Disulfide-Isomerases; D051381:Rats; D018167:Receptors, Calcitriol / Q000378:metabolism; D013256:Steroids / Q000378:metabolism*
D002352:Carrier Proteins; D006360:Heat-Shock Proteins; D018167:Receptors, Calcitriol; D013256:Steroids; D007535:Isomerases; C513196:PDIA3 protein, rat; D019704:Protein Disulfide-Isomerases; D002118:Calcium