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Sucrose synthase isoforms in cultured tobacco cells

Matic, Sandra LU ; Åkerlund, Hans-Erik LU ; Everitt, Einar LU and Widell, Susanne LU (2004) In Plant Physiology and Biochemistry 42(4). p.299-306
Abstract
The plant enzyme sucrose synthase (SuSy; EC 2.4.1.13) catalyzes the reversible conversion of sucrose and UDP into UDP-glucose (UDP-Glc) and fructose. The enzyme exists in different isoforms and is both located in the cytosol, membrane-bound and associated to the actin cytoskeleton. We here investigate sucrose synthase from tobacco (Nicotiana tabacum L.) BY-2 heterotrophic cell suspensions. Two different isoforms of sucrose synthase SuSy1 and SuSy2, could be purified from cytosolic extracts of these cells using a combination of poly(ethylene glycol) (PEG) precipitation, gel filtration, ion-exchange chromatography and affinity chromatography. They were clearly distinct. both with regard to the binding to the ion-exchange column and with... (More)
The plant enzyme sucrose synthase (SuSy; EC 2.4.1.13) catalyzes the reversible conversion of sucrose and UDP into UDP-glucose (UDP-Glc) and fructose. The enzyme exists in different isoforms and is both located in the cytosol, membrane-bound and associated to the actin cytoskeleton. We here investigate sucrose synthase from tobacco (Nicotiana tabacum L.) BY-2 heterotrophic cell suspensions. Two different isoforms of sucrose synthase SuSy1 and SuSy2, could be purified from cytosolic extracts of these cells using a combination of poly(ethylene glycol) (PEG) precipitation, gel filtration, ion-exchange chromatography and affinity chromatography. They were clearly distinct. both with regard to the binding to the ion-exchange column and with regard to their kinetic and regulatory properties. SuSy 1, the more abundant species, showed lower V-max and K-m for sucrose and UDP compared to the less abundant SuSy2. The activity of SuSy2 in the breakdown direction was stimulated by 60% by actin, in contrast to that of SuSy 1, which showed a 17% inhibition. An indication of interaction between SuSy I and actin was obtained by partitioning in aqueous Dextran-PEG two-phase systems. Furthermore, fructose 2,6-bisphosphate (F26BP) at micromolar concentrations stimulated SuSy2 in the presence of actin while SuSy I was strongly inhibited by fructose. Possible roles of these two isoforms in the sucrose turnover in BY-2 cells are discussed. (C) 2004 Elsevier SAS. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Two-phase partitioning, Tobacco, Sucrose synthase, Sucrolysis, 6-bisphosphate, Fructose 2, Actin, BY-2 cells
in
Plant Physiology and Biochemistry
volume
42
issue
4
pages
299 - 306
publisher
Elsevier
external identifiers
  • pmid:15120114
  • wos:000221421500005
  • scopus:2342592684
ISSN
1873-2690
DOI
10.1016/j.plaphy.2004.01.009
language
English
LU publication?
yes
id
5ea70c96-5160-44a9-ad1c-661690bbd1cb (old id 138587)
date added to LUP
2007-07-06 11:36:54
date last changed
2017-12-03 03:38:14
@article{5ea70c96-5160-44a9-ad1c-661690bbd1cb,
  abstract     = {The plant enzyme sucrose synthase (SuSy; EC 2.4.1.13) catalyzes the reversible conversion of sucrose and UDP into UDP-glucose (UDP-Glc) and fructose. The enzyme exists in different isoforms and is both located in the cytosol, membrane-bound and associated to the actin cytoskeleton. We here investigate sucrose synthase from tobacco (Nicotiana tabacum L.) BY-2 heterotrophic cell suspensions. Two different isoforms of sucrose synthase SuSy1 and SuSy2, could be purified from cytosolic extracts of these cells using a combination of poly(ethylene glycol) (PEG) precipitation, gel filtration, ion-exchange chromatography and affinity chromatography. They were clearly distinct. both with regard to the binding to the ion-exchange column and with regard to their kinetic and regulatory properties. SuSy 1, the more abundant species, showed lower V-max and K-m for sucrose and UDP compared to the less abundant SuSy2. The activity of SuSy2 in the breakdown direction was stimulated by 60% by actin, in contrast to that of SuSy 1, which showed a 17% inhibition. An indication of interaction between SuSy I and actin was obtained by partitioning in aqueous Dextran-PEG two-phase systems. Furthermore, fructose 2,6-bisphosphate (F26BP) at micromolar concentrations stimulated SuSy2 in the presence of actin while SuSy I was strongly inhibited by fructose. Possible roles of these two isoforms in the sucrose turnover in BY-2 cells are discussed. (C) 2004 Elsevier SAS. All rights reserved.},
  author       = {Matic, Sandra and Åkerlund, Hans-Erik and Everitt, Einar and Widell, Susanne},
  issn         = {1873-2690},
  keyword      = {Two-phase partitioning,Tobacco,Sucrose synthase,Sucrolysis,6-bisphosphate,Fructose 2,Actin,BY-2 cells},
  language     = {eng},
  number       = {4},
  pages        = {299--306},
  publisher    = {Elsevier},
  series       = {Plant Physiology and Biochemistry},
  title        = {Sucrose synthase isoforms in cultured tobacco cells},
  url          = {http://dx.doi.org/10.1016/j.plaphy.2004.01.009},
  volume       = {42},
  year         = {2004},
}