[Diseases Due to the Deficiency in Vitamin K Conversion System and Its Prevention]

Area of Science:

• Biochemistry
• Molecular Biology
• Nutritional Science

Background:

• Vitamin K is vital for blood coagulation and bone metabolism.
• Dietary Vitamin K includes phylloquinone (K1) and menaquinones (MK-n).
• Menaquinone-4 (MK-4) is the predominant form in mammalian tissues, synthesized endogenously.

Purpose of the Study:

• To identify the enzyme responsible for converting dietary Vitamin K forms to MK-4.
• To investigate the physiological roles and significance of UBIAD1-mediated MK-4 synthesis in vivo.

Main Methods:

• Utilized knockout mouse models (systemic and tissue-specific) to study UBIAD1 function.
• Investigated the conversion pathway of Vitamin K1 and MK-n to MK-4.

Main Results:

• Identified UbiA prenyltransferase domain containing protein 1 (UBIAD1) as the key enzyme for Vitamin K conversion to MK-4.
• Established UBIAD1's role in synthesizing the body's primary MK-4 form.

Conclusions:

• UBIAD1 is essential for converting dietary Vitamin K1 and MK-n into tissue MK-4.
• Further research using UBIAD1 knockout models is needed to fully elucidate MK-4's physiological functions and therapeutic potential.