First Author | Nykjaer A | Year | 1999 |
Journal | Cell | Volume | 96 |
Issue | 4 | Pages | 507-15 |
PubMed ID | 10052453 | Mgi Jnum | J:53162 |
Mgi Id | MGI:1331347 | Doi | 10.1016/s0092-8674(00)80655-8 |
Citation | Nykjaer A, et al. (1999) An endocytic pathway essential for renal uptake and activation of the steroid 25-(OH) vitamin D3. Cell 96(4):507-15 |
abstractText | Steroid hormones may enter cells by diffusion through the plasma membrane. However, we demonstrate here that some steroid hormones are taken up by receptor-mediated endocytosis of steroid-carrier complexes. We show that 25-(OH) vitamin D3 in complex with its plasma carrier, the vitamin D-binding protein, is filtered through the glomerulus and reabsorbed in the proximal tubules by the endocytic receptor megalin. Endocytosis is required to preserve 25-(OH) vitamin D3 and to deliver to the cells the precursor for generation of 1,25-(OH)2 vitamin D3, a regulator of the calcium metabolism. Megalin-/- mice are unable to retrieve the steroid from the glomerular filtrate and develop vitamin D deficiency and bone disease. |