Synergistic Interactions between Carotene Ring Hydroxylases Drive Lutein Formation in Plant Carotenoid Biosynthesis

  • Quinlan R
  • Shumskaya M
  • Bradbury L
 et al. 
  • 57


    Mendeley users who have this article in their library.
  • 35


    Citations of this article.


Plant carotenoids play essential roles in photosynthesis, photoprotection, and as precursors to apocarotenoids. The plastid-localized carotenoid biosynthetic pathway is mediated by well-defined nucleus-encoded enzymes. However, there is a major gap in understanding the nature of protein interactions and pathway complexes needed to mediate carotenogenesis. In this study, we focused on carotene ring hydroxylation, which is performed by two structurally distinct classes of enzymes, the P450 CYP97A and CYP97C hydroxylases and the nonheme diiron HYD enzymes. The CYP97A and HYD enzymes both function in the hydroxylation of β-rings in carotenes, but we show that they are not functionally interchangeable. The formation of lutein, which involves hydroxylation of both β- and ε-rings, was shown to require the coexpression of CYP97A and CYP97C enzymes. These enzymes were also demonstrated to interact in vivo and in vitro, as determined using bimolecular fluorescence complementation and a pull-down assay, respectively. We discuss the role of specific hydroxylase enzyme interactions in promoting pathway flux and preventing the formation of pathway dead ends. These findings will facilitate efforts to manipulate carotenoid content and composition for improving plant adaptation to climate change and/or for enhancing nutritionally important carotenoids in food crops.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text


  • R. F. Quinlan

  • M. Shumskaya

  • L. M. T. Bradbury

  • J. Beltran

  • C. Ma

  • E. J. Kennelly

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free