The kidney in vitamin B12 and folate homeostasis: characterization of receptors for tubular uptake of vitamins and carrier proteins.

@article{Birn2006TheKI,
  title={The kidney in vitamin B12 and folate homeostasis: characterization of receptors for tubular uptake of vitamins and carrier proteins.},
  author={Henrik Birn},
  journal={American journal of physiology. Renal physiology},
  year={2006},
  volume={291 1},
  pages={
          F22-36
        }
}
  • H. Birn
  • Published 1 July 2006
  • Biology, Medicine
  • American journal of physiology. Renal physiology
Over the past 10 years, animal studies have uncovered the molecular mechanisms for the renal tubular recovery of filtered vitamin and vitamin carrier proteins. [] Key Result The folate receptor is important for the conservation of folate, mediating endocytosis of the vitamin. Interaction between the structurally closely related, soluble folate-binding protein and megalin suggests that megalin plays an additional role in the uptake of folate bound to filtered folate-binding protein.
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Citation Type

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The role of the kidneys in folate homeostasis, the molecular basis of folate handling by the kidneys, and the use of high dose folic acid as a model of acute kidney injury are described.
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    Sub-cellular biochemistry
  • 2012
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The review focuses on the molecular mechanisms of cobalamin transport with emphasis on interaction of corrinoids with the specific proteins and protein-receptor recognition.
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It is hypothesize that excessive intake of folic acid depletes serum holotranscobalamin (holoTC), thereby decreasing active vitamin B-12 in the circulation and limiting its availability for tissues, and suggests that, in a depleted state, vitaminB-12 is diverted to the hematopoietic system or the kidney.
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The chronic ethanol ingestion led to decreased folate uptake in liver, which was associated with the decreased number of transporter molecules in the lipid rafts that can be ascribed to the reduced synthesis of these transporters.
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Basic and clinical features of this multistep pathway with emphasis on gastrointestinal transport of B12 are described, including a coherent pathway for B12 trafficking from food to the body's cells.
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Reduced Proximal Tubular Expression of Megalin and Neonatal Fc Receptor in Proteinuria: The Role of Matrix Metalloproteinases
TLDR
Investigation of the expression and turnover of megalin and FcRn in proteinuria and the possible mechanisms underlying down-regulation of expression of these receptors found blockade of MMP in proteinuric animals significantly reduced the expression ofThese markers in the kidney and abrogated the progression of interstitial inflammation and fibrosis.
Characterization of soluble folate receptors (folate binding proteins) in humans. Biological roles and clinical potentials in infection and malignancy.
  • J. Holm, S. Hansen
  • Biology, Medicine
    Biochimica et biophysica acta. Proteins and proteomics
  • 2020
Subcellular localization and distribution of the reduced folate carrier in normal rat tissues
TLDR
The results demonstrated that rRfc1 is expressed almost ubiquitously but to very different levels, and the predominant tissue distribution supports the essential role of Rfc1 in physiological folate homeostasis.
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