Harmonizome 3.0

transcobalamin I (vitamin B12 binding protein, R binder family)

This gene encodes a member of the vitamin B12-binding protein family. This family of proteins, alternatively referred to as R binders, is expressed in various tissues and secretions. This protein is a major constituent of secondary granules in neutrophils and facilitates the transport of cobalamin into cells. [provided by RefSeq, Jul 2008]

methylmalonic aciduria (cobalamin deficiency) cblA type

The protein encoded by this gene is involved in the translocation of cobalamin into the mitochondrion, where it is used in the final steps of adenosylcobalamin synthesis. Adenosylcobalamin is a coenzyme required for the activity of methylmalonyl-CoA mutase. Defects in this gene are a cause of methylmalonic aciduria. [provided by RefSeq, Jul 2008]

methylmalonic aciduria (cobalamin deficiency) cblB type

This gene encodes a protein that catalyzes the final step in the conversion of vitamin B(12) into adenosylcobalamin (AdoCbl), a vitamin B12-containing coenzyme for methylmalonyl-CoA mutase. Mutations in the gene are the cause of vitamin B12-dependent methylmalonic aciduria linked to the cblB complementation group. Alternatively spliced transcript variants have been found. [provided by RefSeq, Apr 2011]

methylmalonic aciduria (cobalamin deficiency) cblC type, with homocystinuria

The exact function of the protein encoded by this gene is not known, however, its C-terminal region shows similarity to TonB, a bacterial protein involved in energy transduction for cobalamin (vitamin B12) uptake. Hence, it is postulated that this protein may have a role in the binding and intracellular trafficking of cobalamin. Mutations in this gene are associated with methylmalonic aciduria and homocystinuria type cblC. [provided by RefSeq, Oct 2009]

methylmalonic aciduria (cobalamin deficiency) cblD type, with homocystinuria

This gene encodes a mitochondrial protein that is involved in an early step of vitamin B12 metabolism. Vitamin B12 (cobalamin) is essential for normal development and survival in humans. Mutations in this gene cause methylmalonic aciduria and homocystinuria type cblD (MMADHC), a disorder of cobalamin metabolism that is characterized by decreased levels of the coenzymes adenosylcobalamin and methylcobalamin. Pseudogenes have been identified on chromosomes 11 and X.[provided by RefSeq, Nov 2008]

methylmalonic aciduria (cobalamin deficiency) cblD type, with homocystinuria pseudogene

methylmalonic aciduria (cobalamin deficiency) cblD type, with homocystinuria pseudogene

nuclear pore complex interacting protein family member B12

Predicted to be located in membrane. [provided by Alliance of Genome Resources, Mar 2025]

pyridoxal (pyridoxine, vitamin B6) kinase

The protein encoded by this gene phosphorylates vitamin B6, a step required for the conversion of vitamin B6 to pyridoxal-5-phosphate, an important cofactor in intermediary metabolism. The encoded protein is cytoplasmic and probably acts as a homodimer. Alternatively spliced transcript variants have been described, but their biological validity has not been determined. [provided by RefSeq, Jul 2008]

pyridoxal (pyridoxine, vitamin B6) phosphatase

Pyridoxal 5-prime-phosphate (PLP) is the active form of vitamin B6 that acts as a coenzyme in maintaining biochemical homeostasis. The preferred degradation route from PLP to 4-pyridoxic acid involves the dephosphorylation of PLP by PDXP (Jang et al., 2003 [PubMed 14522954]).[supplied by OMIM, Mar 2008]

gastric intrinsic factor (vitamin B synthesis)

This gene is a member of the cobalamin transport protein family. It encodes a glycoprotein secreted by parietal cells of the gastric mucosa and is required for adequate absorption of vitamin B12. Vitamin B12 is necessary for erythrocyte maturation and mutations in this gene may lead to congenital pernicious anemia. [provided by RefSeq, Jul 2008]

vitamin K epoxide reductase complex, subunit 1

This gene encodes the catalytic subunit of the vitamin K epoxide reductase complex, which is responsible for the reduction of inactive vitamin K 2,3-epoxide to active vitamin K in the endoplasmic reticulum membrane. Vitamin K is a required co-factor for carboxylation of glutamic acid residues by vitamin K-dependent gamma-carboxylase in blood-clotting enzymes. Allelic variation in this gene is associated with vitamin k-dependent clotting factors combined deficiency of 2, and increased resistance or sensitivity to warfarin, an inhibitor of vitamin K epoxide reductase. Pseudogenes of this gene are located on chromosomes 1 and X. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2015]

vitamin K epoxide reductase complex, subunit 1-like 1

This gene encodes an enzyme important in the vitamin K cycle, which is involved in the carboxylation of glutamate residues present in vitamin K-dependent proteins. The encoded enzyme catalyzes the de-epoxidation of vitamin K 2,3-epoxide. Oxidative stress may upregulate expression of this gene and the encoded protein may protect cells and membrane proteins form oxidative damage. This gene and a related gene (Gene ID: 79001) may have arisen by gene duplication of an ancestral gene. [provided by RefSeq, Oct 2016]

vitamin K epoxide reductase complex, subunit 1-like 1 pseudogene

vitamin D (1,25- dihydroxyvitamin D3) receptor

This gene encodes vitamin D3 receptor, which is a member of the nuclear hormone receptor superfamily of ligand-inducible transcription factors. This receptor also functions as a receptor for the secondary bile acid, lithocholic acid. Downstream targets of vitamin D3 receptor are principally involved in mineral metabolism, though this receptor regulates a variety of other metabolic pathways, such as those involved in immune response and cancer. Mutations in this gene are associated with type II vitamin D-resistant rickets. A single nucleotide polymorphism in the initiation codon results in an alternate translation start site three codons downstream. Alternatively spliced transcript variants encoding different isoforms have been described for this gene. A recent study provided evidence for translational readthrough in this gene, and expression of an additional C-terminally extended isoform via the use of an alternative in-frame translation termination codon. [provided by RefSeq, Jun 2018]

Vitamin B6 plasma level QTL 1

group-specific component (vitamin D binding protein)

The protein encoded by this gene belongs to the albumin gene family. It is a multifunctional protein found in plasma, ascitic fluid, cerebrospinal fluid and on the surface of many cell types. It binds to vitamin D and its plasma metabolites and transports them to target tissues. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Feb 2011]

protein Z, vitamin K-dependent plasma glycoprotein

This gene encodes a liver vitamin K-dependent glycoprotein that is synthesized in the liver and secreted into the plasma. The encoded protein plays a role in regulating blood coagulation by complexing with protein Z-dependent protease inhibitor to directly inhibit activated factor X at the phospholipid surface. Deficiencies in this protein are associated with an increased risk of ischemic arterial diseases and fetal loss. Mutations in this gene are the cause of protein Z deficiency. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Jan 2012]