Details
| Original language | English |
|---|---|
| Pages (from-to) | 510-528 |
| Number of pages | 19 |
| Journal | The plant cell |
| Volume | 35 |
| Issue number | 1 |
| Early online date | 7 Nov 2022 |
| Publication status | Published - 2 Jan 2023 |
Abstract
In nucleotide metabolism, nucleoside kinases recycle nucleosides into nucleotides-a process called nucleoside salvage. Nucleoside kinases for adenosine, uridine, and cytidine have been characterized from many organisms, but kinases for inosine and guanosine salvage are not yet known in eukaryotes and only a few such enzymes have been described from bacteria. Here we identified Arabidopsis thaliana PLASTID NUCLEOSIDE KINASE 1 (PNK1), an enzyme highly conserved in plants and green algae belonging to the Phosphofructokinase B family. We demonstrate that PNK1 from A. thaliana is located in plastids and catalyzes the phosphorylation of inosine, 5-aminoimidazole-4-carboxamide-1-β-d-ribose (AICA ribonucleoside), and uridine but not guanosine in vitro, and is involved in inosine salvage in vivo. PNK1 mutation leads to increased flux into purine nucleotide catabolism and, especially in the context of defective uridine degradation, to over-accumulation of uridine and UTP as well as growth depression. The data suggest that PNK1 is involved in feedback regulation of purine nucleotide biosynthesis and possibly also pyrimidine nucleotide biosynthesis. We additionally report that cold stress leads to accumulation of purine nucleotides, probably by inducing nucleotide biosynthesis, but that this adjustment of nucleotide homeostasis to environmental conditions is not controlled by PNK1.
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Plant Science
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In: The plant cell, Vol. 35, No. 1, 02.01.2023, p. 510-528.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - A plastid nucleoside kinase is involved in inosine salvage and control of purine nucleotide biosynthesis
AU - Chen, Xiaoguang
AU - Kim, Sang Hoon
AU - Rhee, Sangkee
AU - Witte, Claus Peter
N1 - Funding Information: X.C. was funded by the Chinese Scholarship Council (PhD fellowship 201703250066) and a fellowship of the Institute of Plant Nutrition of LUH. The research was supported by grants of the Deutsche Forschungsgemeinschaft to C.P.W. (WI3411/7-1; WI3411/8-1) and INST 187/741-1 FUGG. Acknowledgments: We thank Andre ́ Specht and Hildegard Tho ̈lke for technical assistance and Markus Niehaus and Mingjia Chen for general support. We also thank Marco Herde and Henryk Straube for critical discussions.
PY - 2023/1/2
Y1 - 2023/1/2
N2 - In nucleotide metabolism, nucleoside kinases recycle nucleosides into nucleotides-a process called nucleoside salvage. Nucleoside kinases for adenosine, uridine, and cytidine have been characterized from many organisms, but kinases for inosine and guanosine salvage are not yet known in eukaryotes and only a few such enzymes have been described from bacteria. Here we identified Arabidopsis thaliana PLASTID NUCLEOSIDE KINASE 1 (PNK1), an enzyme highly conserved in plants and green algae belonging to the Phosphofructokinase B family. We demonstrate that PNK1 from A. thaliana is located in plastids and catalyzes the phosphorylation of inosine, 5-aminoimidazole-4-carboxamide-1-β-d-ribose (AICA ribonucleoside), and uridine but not guanosine in vitro, and is involved in inosine salvage in vivo. PNK1 mutation leads to increased flux into purine nucleotide catabolism and, especially in the context of defective uridine degradation, to over-accumulation of uridine and UTP as well as growth depression. The data suggest that PNK1 is involved in feedback regulation of purine nucleotide biosynthesis and possibly also pyrimidine nucleotide biosynthesis. We additionally report that cold stress leads to accumulation of purine nucleotides, probably by inducing nucleotide biosynthesis, but that this adjustment of nucleotide homeostasis to environmental conditions is not controlled by PNK1.
AB - In nucleotide metabolism, nucleoside kinases recycle nucleosides into nucleotides-a process called nucleoside salvage. Nucleoside kinases for adenosine, uridine, and cytidine have been characterized from many organisms, but kinases for inosine and guanosine salvage are not yet known in eukaryotes and only a few such enzymes have been described from bacteria. Here we identified Arabidopsis thaliana PLASTID NUCLEOSIDE KINASE 1 (PNK1), an enzyme highly conserved in plants and green algae belonging to the Phosphofructokinase B family. We demonstrate that PNK1 from A. thaliana is located in plastids and catalyzes the phosphorylation of inosine, 5-aminoimidazole-4-carboxamide-1-β-d-ribose (AICA ribonucleoside), and uridine but not guanosine in vitro, and is involved in inosine salvage in vivo. PNK1 mutation leads to increased flux into purine nucleotide catabolism and, especially in the context of defective uridine degradation, to over-accumulation of uridine and UTP as well as growth depression. The data suggest that PNK1 is involved in feedback regulation of purine nucleotide biosynthesis and possibly also pyrimidine nucleotide biosynthesis. We additionally report that cold stress leads to accumulation of purine nucleotides, probably by inducing nucleotide biosynthesis, but that this adjustment of nucleotide homeostasis to environmental conditions is not controlled by PNK1.
UR - http://www.scopus.com/inward/record.url?scp=85145425054&partnerID=8YFLogxK
U2 - 10.1093/plcell/koac320
DO - 10.1093/plcell/koac320
M3 - Article
C2 - 36342213
AN - SCOPUS:85145425054
VL - 35
SP - 510
EP - 528
JO - The plant cell
JF - The plant cell
SN - 1040-4651
IS - 1
ER -