[Molecular mechanisms of vitamin K action in the bone homeostasis].
Vitamin K is used as an anti-osteoporosis drug in Japan. Moreover, vitamin K intake has been found to decrease hip fracture risk. In the bone homeostasis, vitamin K action is mediated through two molecular mechanisms: posttranslational modification of proteins, and regulation of gene expression. The former is vitamin K-dependent carboxylation, in which vitamin K functions as an essential cofactor for modification of glutamic acid residues to gamma-carboxyglutamic acid residues. The latter is a novel mechanism that regulates the transcription of target genes by vitamin K through activation of steroid and xenobiotic receptor (SXR). The two mechanisms may coordinately contribute to vitamin K function in the bone metabolism.
Ichikawa
Tomoe
T
Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical School.
Inoue
Satoshi
S
D000818:Animals; D001842:Bone and Bones / Q000187:drug effects*; D002264:Carboxylic Acids / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D006801:Humans; D010024:Osteoporosis / Q000188:drug therapy; D011987:Receptors, Steroid / Q000502:physiology; D014812:Vitamin K / Q000494:pharmacology* / Q000627:therapeutic use
D002264:Carboxylic Acids; D005971:Glutamates; D011987:Receptors, Steroid; D014812:Vitamin K