Identification, subcellular localization and biochemical characterization of water‐soluble heteroglycans (SHG) in leaves of Arabidopsis thaliana L.: distinct SHG reside in the cytosol and in the apoplast
Open Access
- 5 July 2005
- journal article
- Published by Wiley in The Plant Journal
- Vol. 43 (4) , 568-585
- https://doi.org/10.1111/j.1365-313x.2005.02475.x
Abstract
Water-soluble heteroglycans (SHG) were isolated from leaves of wild-type Arabidopsis thaliana L. and from two starch-deficient mutants. Major constituents of the SHG are arabinose, galactose, rhamnose, and glucose. SHG was separated into low (10 kDa; SHGL) molecular weight compounds. SHGS was resolved into approximately 25 distinct oligoglycans by ion exchange chromatography. SHGL was further separated into two subfractions, designated as subfraction I and II, by field flow fractionation. For the intracellular localization of the various SHG compounds several approaches were chosen: first, leaf material was subjected to non-aqueous fractionation. The apolar gradient fractions were characterized by monitoring markers and were used as starting material for the SHG isolation. Subfraction I and SHGS exhibited a distribution similar to that of cytosolic markers whereas subfraction II cofractionated with crystalline cellulose. Secondly, intact organelles were isolated and used for SHG isolation. Preparations of intact organelles (mitochondria plus peroxisomes) contained no significant amount of any heteroglycan. In isolated intact microsomes a series of oligoglycans was recovered but neither subfraction I nor II. In in vitro assays using glucose 1-phosphate and recombinant cytosolic (Pho 2) phosphorylase both SHGS and subfraction I acted as glucosyl acceptor whereas subfraction II was essentially inactive. Rabbit muscle phosphorylase a did not utilize any of the plant glycans indicating a specific Pho 2–glycan interaction. As revealed by in vivo labeling experiments using 14CO2 carbon fluxes into subfraction I and II differed. Furthermore, in leaves the pool size of subfraction I varied during the light–dark regime.Keywords
This publication has 45 references indexed in Scilit:
- α-Amylase Is Not Required for Breakdown of Transitory Starch in Arabidopsis LeavesJournal of Biological Chemistry, 2005
- β-Maltose Is the Metabolically Active Anomer of Maltose during Transitory Starch DegradationPlant Physiology, 2005
- Identification of a Novel Enzyme Required for Starch Metabolism in Arabidopsis Leaves. The Phosphoglucan, Water DikinasePlant Physiology, 2005
- Recent developments in understanding the regulation of starch metabolism in higher plantsJournal of Experimental Botany, 2004
- Adjustment of diurnal starch turnover to short days: depletion of sugar during the night leads to a temporary inhibition of carbohydrate utilization, accumulation of sugars and post‐translational activation of ADP‐glucose pyrophosphorylase in the following light periodThe Plant Journal, 2004
- An Arabidopsis Calcium-Dependent Protein Kinase Is Associated with the Endoplasmic ReticulumPlant Physiology, 2002
- Light scattering and the absolute characterization of macromoleculesPublished by Elsevier ,2001
- Amino Acid and Sucrose Content Determined in the Cytosolic, Chloroplastic, and Vacuolar Compartments and in the Phloem Sap of Spinach LeavesPlant Physiology, 1991
- Polysaccharide Fraction from Higher Plants which Strongly Interacts with the Cytosolic Phosphorylase IsozymePlant Physiology, 1990
- Isolation and Characterization of a Starchless Mutant of Arabidopsis thaliana (L.) Heynh Lacking ADPglucose Pyrophosphorylase ActivityPlant Physiology, 1988