{c}

<UBIAD1> is a membrane-associated <prenyltransferase> with a demonstrated role in making <menaquinone-4>, a <Vitamin K> form. It attaches an <isoprene>-derived side chain to a suitable precursor, including <menadione>. It should be distinguished from <menaquinone-4>, the small <molecule> produced by the reaction.<Identification of UBIAD1 as a novel human menaquinone-4 biosynthetic enzyme by Kimie Nakagawa and others>[Abstract; identification of a human MK-4 biosynthetic enzyme]{ref}

In 2010, <siRNA>-mediated reduction of <UBIAD1> in human <cells> decreased labelled-product formation. Expressing <UBIAD1> in insect <cells> enabled production of labelled <menaquinone-4>, whose structure was checked using <deuterium> <nuclear magnetic resonance>.<Identification of UBIAD1 as a novel human menaquinone-4 biosynthetic enzyme by Kimie Nakagawa and others>[Abstract and Figures2–3]{ref} Loss-of-function and gain-of-function comparisons thus connected a particular <protein> to a defined chemical transformation; neither expression alone nor a fluorescent localization image would establish that transformation.


 UBIAD1 (source code)