A purine nucleoside phosphorylase in Solanum tuberosum L. (potato) with specificity for cytokinins contributes to the duration of tuber endodormancy

Autor: Colin G. N. Turnbull, Celia M. James, Barbara J. Warnes, Jennifer R. Bromley, David E. Hanke, Christine A. Newell, Jamie C. P. Thomson
Rok vydání: 2013
Předmět:
INTERCONVERSION
Cytokinins
Time Factors
Purine nucleoside phosphorylase
Biochemistry
Plant Proteins
Dietary
chemistry.chemical_compound
Purine metabolism
BUD DORMANCY
PLASMODIUM-FALCIPARUM
food and beverages
11 Medical And Health Sciences
ARABIDOPSIS
Plant Dormancy
Plant Tubers
SEASONAL PATTERN
03 Chemical Sciences
Life Sciences & Biomedicine
Adenosine nucleosidase
medicine.drug
Protein Binding
Biochemistry & Molecular Biology
purine riboside phosphorylase
Molecular Sequence Data
Biology
plant hormone
METABOLISM
Glycogen phosphorylase
cytokinin
medicine
Amino Acid Sequence
PLANT
ADENOSINE NUCLEOSIDASE
Molecular Biology
Solanum tuberosum
WHEAT-GERM
Science & Technology
Plant Extracts
fungi
Cell Biology
Riboside
06 Biological Sciences
Molecular biology
Adenosine
GENE
endodormancy
Purine-nucleoside phosphorylase activity
chemistry
Purine-Nucleoside Phosphorylase
Vegetable Proteins
Isopentenyladenosine
Zdroj: The Biochemical journal. 458(2)
ISSN: 1470-8728
Popis: StCKP1 (Solanum tuberosum cytokinin riboside phosphorylase) catalyses the interconversion of the N9-riboside form of the plant hormone CK (cytokinin), a subset of purines, with its most active free base form. StCKP1 prefers CK to unsubstituted aminopurines. The protein was discovered as a CK-binding activity in extracts of tuberizing potato stolon tips, from which it was isolated by affinity chromatography. The N-terminal amino acid sequence matched the translation product of a set of ESTs, enabling a complete mRNA sequence to be obtained by RACE-PCR. The predicted polypeptide includes a cleavable signal peptide and motifs for purine nucleoside phosphorylase activity. The expressed protein was assayed for purine nucleoside phosphorylase activity against CKs and adenine/adenosine. Isopentenyladenine, trans-zeatin, dihydrozeatin and adenine were converted into ribosides in the presence of ribose 1-phosphate. In the opposite direction, isopentenyladenosine, trans-zeatin riboside, dihydrozeatin riboside and adenosine were converted into their free bases in the presence of Pi. StCKP1 had no detectable ribohydrolase activity. Evidence is presented that StCKP1 is active in tubers as a negative regulator of CKs, prolonging endodormancy by a chill-reversible mechanism.
Databáze: OpenAIRE
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