Key Pathways and Regulators of Vitamin K Function and Intermediary Metabolism.

Key Pathways and Regulators of Vitamin K Function and Intermediary Metabolism.
Annu Rev Nutr. 2018 Jun 01;:
Authors: Shearer MJ, Okano T
Abstract
Vitamin K (VK) is an essential cofactor for the post-translational conversion of peptide-bound glutamate to γ-carboxyglutamate. The resultant vitamin K-dependent proteins are known or postulated to possess a variety of biological functions, chiefly in the maintenance of hemostasis. The vitamin K cycle is a cellular pathway that drives γ-carboxylation and recycling of VK via γ-carboxyglutamyl carboxylase (GGCX) and vitamin K epoxide reductase (VKOR), respectively. In this review, we show how novel molecular biological approaches are providing new insights into the pathophysiological mechanisms caused by rare mutations of both GGCX and VKOR. We also discuss how other protein regulators influence the intermediary metabolism of VK, first through intestinal absorption and second through a pathway that converts some dietary phylloquinone to menadione, which is prenylated to menaquinone-4 (MK-4) in target tissues by UBIAD1. The contribution of MK-4 synthesis to VK functions is yet to be revealed. Expected final online publication date for the Annual Review of Nutrition Volume 38 is August 21, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
PMID: 29856932 [PubMed - as supplied by publisher]

Source: Annual Review of Nutrition - June 1, 2018 Category: Nutrition Authors: Shearer MJ, Okano T Tags: Annu Rev Nutr Source Type: research