title: Recreating the synthesis of starch granules in yeast.
abstract: Starch, as the major nutritional component of our staple crops and a feedstock for industry, is a vital plant product. It is composed of glucose polymers that form massive semi-crystalline granules. Its precise structure and composition determine its functionality and thus applications; however, there is no versatile model system allowing the relationships between the biosynthetic apparatus, glucan structure and properties to be explored. Here, we expressed the core Arabidopsis starch-biosynthesis pathway inSaccharomyces cerevisiaepurged of its endogenous glycogen-metabolic enzymes. Systematic variation of the set of biosynthetic enzymes illustrated how each affects glucan structure and solubility. Expression of the complete set resulted in dense, insoluble granules with a starch-like semi-crystalline organization, demonstrating that this system indeed simulates starch biosynthesis. Thus, the yeast system has the potential to accelerate starch research and help create a holistic understanding of starch granule biosynthesis, providing a basis for the targeted biotechnological improvement of crops.
authors.affiliation: Department of Biology, ETH Zürich, Zürich, Switzerland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Pfister
authors.affiliation: Health Sciences and Technology, ETH Zürich, Zurich, Switzerland.
authors.forename: Antoni
authors.initials: A
authors.lastname: Sánchez-Ferrer
authors.affiliation: Paul Scherrer Institut, Villigen, Switzerland.
authors.forename: Ana
authors.initials: A
authors.lastname: Diaz
authors.affiliation: Department of Biology, ETH Zürich, Zürich, Switzerland.
authors.forename: Kuanjen
authors.initials: K
authors.lastname: Lu
authors.affiliation: Department of Biology, ETH Zürich, Zürich, Switzerland.
authors.forename: Caroline
authors.initials: C
authors.lastname: Otto
authors.affiliation: Paul Scherrer Institut, Villigen, Switzerland.
authors.forename: Mirko
authors.initials: M
authors.lastname: Holler
authors.affiliation: Paul Scherrer Institut, Villigen, Switzerland.
authors.forename: Farooque Razvi
authors.initials: FR
authors.lastname: Shaik
authors.affiliation: Department of Biology, ETH Zürich, Zürich, Switzerland.
authors.forename: Florence
authors.initials: F
authors.lastname: Meier
authors.affiliation: Health Sciences and Technology, ETH Zürich, Zurich, Switzerland.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Mezzenga
authors.affiliation: Department of Biology, ETH Zürich, Zürich, Switzerland.
authors.forename: Samuel C
authors.identifier: 0000-0002-2791-0915
authors.initials: SC
authors.lastname: Zeeman
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D053898:Biosynthetic Pathways / Q000235:genetics*; D003001:Cloning, Molecular; D015870:Gene Expression; D060847:Metabolic Engineering; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D013213:Starch / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D013213:Starch
keywords: <i>a. thaliana</i>; S. cerevisiae; amylopectin; biochemistry; metabolic engineering; plant biology; starch biosynthesis