Regulation of a plant SNF1-related protein kinase by glucose-6-phosphate

Dikran Toroser, Zvi Plaut, Steven C. Huber

Research output: Contribution to journalArticle

Abstract

One of the major protein kinases (PK(III)) that phosphorylates serine-158 of spinach sucrose-phosphate synthase (SPS), which is responsible for light/dark modulation of activity, is known to be a member of the SNF1-related family of protein kinases. In the present study, we have developed a fluorescence-based continuous assay for measurement of PK(III) activity. Using the continuous assay, along with the fixed-time-point 32P-incorporation assay, we demonstrate that PK(III) activity is inhibited by glucose-6-phosphate (Glc-6-P). Relative inhibition by Glc-6-P was increased by decreasing pH from 8.5 to 5.5 and by reducing the concentration of Mg2+ in the assay from 10 to 2 mM. Under likely physiological conditions (pH 7.0 and 2 mM Mg2+), 10 mm Glc-6-P inhibited kinase activity approximately 70%. Inhibition by Glc-6-P could not be ascribed to contaminants in the commercial preparations. Other metabolites inhibited PK(III) in the following order: Glc-6-P > mannose-6-P, fructose-1,6P2 > ribose-5-P, 3-PGA, fructose-6-P. Inorganic phosphate, Glc, and AMP were not inhibitory, and free Glc did not reverse the inhibition by Glc-6-P. Because SNF1-related protein kinases are thought to function broadly in the regulation of enzyme activity and gene expression, Glc-6-P inhibition of PK(III) activity potentially provides a mechanism for metabolic regulation of the reactions catalyzed by these important protein kinases.

Original languageEnglish (US)
Pages (from-to)403-411
Number of pages9
JournalPlant physiology
Volume123
Issue number1
StatePublished - May 1 2000

Fingerprint

Glucose-6-Phosphate
glucose 6-phosphate
protein kinases
assays
Fructose
sucrose-phosphate synthase
Protein Kinases
fructose
Prostaglandins A
Ribose
Spinacia oleracea
ribose
Adenosine Monophosphate
Mannose
mannose
spinach
serine
Serine
SNF1-related protein kinases
phosphotransferases (kinases)

ASJC Scopus subject areas

  • Physiology
  • Genetics
  • Plant Science

Cite this

Toroser, D., Plaut, Z., & Huber, S. C. (2000). Regulation of a plant SNF1-related protein kinase by glucose-6-phosphate. Plant physiology, 123(1), 403-411.

Regulation of a plant SNF1-related protein kinase by glucose-6-phosphate. / Toroser, Dikran; Plaut, Zvi; Huber, Steven C.

In: Plant physiology, Vol. 123, No. 1, 01.05.2000, p. 403-411.

Research output: Contribution to journalArticle

Toroser, D, Plaut, Z & Huber, SC 2000, 'Regulation of a plant SNF1-related protein kinase by glucose-6-phosphate', Plant physiology, vol. 123, no. 1, pp. 403-411.
Toroser D, Plaut Z, Huber SC. Regulation of a plant SNF1-related protein kinase by glucose-6-phosphate. Plant physiology. 2000 May 1;123(1):403-411.
Toroser, Dikran ; Plaut, Zvi ; Huber, Steven C. / Regulation of a plant SNF1-related protein kinase by glucose-6-phosphate. In: Plant physiology. 2000 ; Vol. 123, No. 1. pp. 403-411.
@article{16fd02a5d68647538b6512a8cf064411,
title = "Regulation of a plant SNF1-related protein kinase by glucose-6-phosphate",
abstract = "One of the major protein kinases (PK(III)) that phosphorylates serine-158 of spinach sucrose-phosphate synthase (SPS), which is responsible for light/dark modulation of activity, is known to be a member of the SNF1-related family of protein kinases. In the present study, we have developed a fluorescence-based continuous assay for measurement of PK(III) activity. Using the continuous assay, along with the fixed-time-point 32P-incorporation assay, we demonstrate that PK(III) activity is inhibited by glucose-6-phosphate (Glc-6-P). Relative inhibition by Glc-6-P was increased by decreasing pH from 8.5 to 5.5 and by reducing the concentration of Mg2+ in the assay from 10 to 2 mM. Under likely physiological conditions (pH 7.0 and 2 mM Mg2+), 10 mm Glc-6-P inhibited kinase activity approximately 70{\%}. Inhibition by Glc-6-P could not be ascribed to contaminants in the commercial preparations. Other metabolites inhibited PK(III) in the following order: Glc-6-P > mannose-6-P, fructose-1,6P2 > ribose-5-P, 3-PGA, fructose-6-P. Inorganic phosphate, Glc, and AMP were not inhibitory, and free Glc did not reverse the inhibition by Glc-6-P. Because SNF1-related protein kinases are thought to function broadly in the regulation of enzyme activity and gene expression, Glc-6-P inhibition of PK(III) activity potentially provides a mechanism for metabolic regulation of the reactions catalyzed by these important protein kinases.",
author = "Dikran Toroser and Zvi Plaut and Huber, {Steven C.}",
year = "2000",
month = "5",
day = "1",
language = "English (US)",
volume = "123",
pages = "403--411",
journal = "Plant Physiology",
issn = "0032-0889",
publisher = "American Society of Plant Biologists",
number = "1",

}

TY - JOUR

T1 - Regulation of a plant SNF1-related protein kinase by glucose-6-phosphate

AU - Toroser, Dikran

AU - Plaut, Zvi

AU - Huber, Steven C.

PY - 2000/5/1

Y1 - 2000/5/1

N2 - One of the major protein kinases (PK(III)) that phosphorylates serine-158 of spinach sucrose-phosphate synthase (SPS), which is responsible for light/dark modulation of activity, is known to be a member of the SNF1-related family of protein kinases. In the present study, we have developed a fluorescence-based continuous assay for measurement of PK(III) activity. Using the continuous assay, along with the fixed-time-point 32P-incorporation assay, we demonstrate that PK(III) activity is inhibited by glucose-6-phosphate (Glc-6-P). Relative inhibition by Glc-6-P was increased by decreasing pH from 8.5 to 5.5 and by reducing the concentration of Mg2+ in the assay from 10 to 2 mM. Under likely physiological conditions (pH 7.0 and 2 mM Mg2+), 10 mm Glc-6-P inhibited kinase activity approximately 70%. Inhibition by Glc-6-P could not be ascribed to contaminants in the commercial preparations. Other metabolites inhibited PK(III) in the following order: Glc-6-P > mannose-6-P, fructose-1,6P2 > ribose-5-P, 3-PGA, fructose-6-P. Inorganic phosphate, Glc, and AMP were not inhibitory, and free Glc did not reverse the inhibition by Glc-6-P. Because SNF1-related protein kinases are thought to function broadly in the regulation of enzyme activity and gene expression, Glc-6-P inhibition of PK(III) activity potentially provides a mechanism for metabolic regulation of the reactions catalyzed by these important protein kinases.

AB - One of the major protein kinases (PK(III)) that phosphorylates serine-158 of spinach sucrose-phosphate synthase (SPS), which is responsible for light/dark modulation of activity, is known to be a member of the SNF1-related family of protein kinases. In the present study, we have developed a fluorescence-based continuous assay for measurement of PK(III) activity. Using the continuous assay, along with the fixed-time-point 32P-incorporation assay, we demonstrate that PK(III) activity is inhibited by glucose-6-phosphate (Glc-6-P). Relative inhibition by Glc-6-P was increased by decreasing pH from 8.5 to 5.5 and by reducing the concentration of Mg2+ in the assay from 10 to 2 mM. Under likely physiological conditions (pH 7.0 and 2 mM Mg2+), 10 mm Glc-6-P inhibited kinase activity approximately 70%. Inhibition by Glc-6-P could not be ascribed to contaminants in the commercial preparations. Other metabolites inhibited PK(III) in the following order: Glc-6-P > mannose-6-P, fructose-1,6P2 > ribose-5-P, 3-PGA, fructose-6-P. Inorganic phosphate, Glc, and AMP were not inhibitory, and free Glc did not reverse the inhibition by Glc-6-P. Because SNF1-related protein kinases are thought to function broadly in the regulation of enzyme activity and gene expression, Glc-6-P inhibition of PK(III) activity potentially provides a mechanism for metabolic regulation of the reactions catalyzed by these important protein kinases.

UR - http://www.scopus.com/inward/record.url?scp=0034073253&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034073253&partnerID=8YFLogxK

M3 - Article

C2 - 10806257

AN - SCOPUS:0034073253

VL - 123

SP - 403

EP - 411

JO - Plant Physiology

JF - Plant Physiology

SN - 0032-0889

IS - 1

ER -