Characterization of the Formation of Branched Short-Chain Fatty Acid: CoAs for Bitter Acid Biosynthesis in Hop Glandular Trichomes

PDF Version Also Available for Download.

Description

Article on the characterization of the formation of branched short-chain fatty acid and CoAs for bitter acid biosynthesis in hop glandular trichomes.

Physical Description

17 p.

Creation Information

Xu, Haiyang; Zhang, Fengxia; Liu, Baoxiu; Huhman, David; Sumner, Lloyd W.; Dixon, R. A. et al. July 2013.

Context

This article is part of the collection entitled: UNT Scholarly Works and was provided by UNT College of Arts and Sciences to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 61 times . More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Authors

Publisher

Provided By

UNT College of Arts and Sciences

The UNT College of Arts and Sciences educates students in traditional liberal arts, performing arts, sciences, professional, and technical academic programs. In addition to its departments, the college includes academic centers, institutes, programs, and offices providing diverse courses of study.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Degree Information

Description

Article on the characterization of the formation of branched short-chain fatty acid and CoAs for bitter acid biosynthesis in hop glandular trichomes.

Physical Description

17 p.

Notes

Abstract: Bitter acids, known for their use as beer flavoring and for their diverse biological activities, are predominantly formed in hop (Humulus lupulus) glandular trichomes. Branched short-chain acyl-CoAs (e.g. isobutyryl-CoA, isovaleryl-CoA and 2-methylbutyryl-CoA), derived from the degradation of branched-chain amino acids (BCAAs), are essential building blocks for the biosynthesis of bitter acids in hops. However, little is known regarding what components are needed to produce and maintain the pool of branched short-chain acyl-CoAs in hop trichomes. Here, we present several lines of evidence that both CoA ligases and thioesterases are likely involved in bitter acid biosynthesis. Recombinant HlCCL2 (carboxyl CoA ligase) protein had high specific activity for isovaleric acid as a substrate (K cat /K m = 4100 s–1 M–1), whereas recombinant HlCCL4 specifically utilized isobutyric acid (K cat /K m = 1800 s–1 M–1) and 2-methylbutyric acid (K cat /K m = 6900 s–1 M–1) as substrates. Both HlCCLs, like hop valerophenone synthase (HlVPS), were expressed strongly in glandular trichomes and localized to the cytoplasm. Co-expression of HlCCL2 and HlCCL4 with HlVPS in yeast led to significant production of acylphloroglucinols (the direct precursors for bitter acid biosynthesis), which further confirmed the biochemical function of these two HlCCLs in vivo. Functional identification of a thioesterase that catalyzed the reverse reaction of CCLs in mitochondria, together with the comprehensive analysis of genes involved BCAA catabolism, supported the idea that cytosolic CoA ligases are required for linking BCAA degradation and bitter acid biosynthesis in glandular trichomes. The evolution and other possible physiological roles of branched short-chain fatty acid:CoA ligases in planta are also discussed.

Copyright © 2013 The Authors. Published by the Molecular Plant Shanghai Editorial Office in Association with Oxford University Press on behalf of CSPB and IPPE, SIBS, CAS.

Source

  • Molecular Plant, 2013, Oxford: Oxford University Press, pp. 1301-1317

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

Publication Information

  • Publication Title: Molecular Plant
  • Volume: 6
  • Issue: 4
  • Page Start: 1301
  • Page End: 1317
  • Peer Reviewed: Yes

Collections

This article is part of the following collection of related materials.

UNT Scholarly Works

Materials from the UNT community's research, creative, and scholarly activities and UNT's Open Access Repository. Access to some items in this collection may be restricted.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • July 2013

Added to The UNT Digital Library

  • April 3, 2014, 8:46 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 3
Total Uses: 61

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Xu, Haiyang; Zhang, Fengxia; Liu, Baoxiu; Huhman, David; Sumner, Lloyd W.; Dixon, R. A. et al. Characterization of the Formation of Branched Short-Chain Fatty Acid: CoAs for Bitter Acid Biosynthesis in Hop Glandular Trichomes, article, July 2013; [Oxford, England]. (digital.library.unt.edu/ark:/67531/metadc282587/: accessed September 21, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT College of Arts and Sciences.