| RRC ID |
3105
|
| 著者 |
Ajjawi I, Rodriguez Milla MA, Cushman J, Shintani DK.
|
| タイトル |
Thiamin pyrophosphokinase is required for thiamin cofactor activation in Arabidopsis.
|
| ジャーナル |
Plant Mol Biol
|
| Abstract |
Thiamin pyrophosphate (TPP) is an essential enzyme cofactor required for the viability of all organisms. Whether derived from exogenous sources or through de novo synthesis, thiamin must be pyrophosphorylated for cofactor activation. The enzyme thiamin pyrophosphokinase (TPK) catalyzes the conversion of free thiamin to TPP in plants and other eukaryotic organisms and is central to thiamin cofactor activation. While TPK activity has been observed in a number of plant species, the corresponding gene/protein has until now not been identified or characterized for its role in thiamin metabolism. Here we report the functional identification of two Arabidopsis TPK genes, AtTPK1 and AtTPK2 and the enzymatic characterization of the corresponding proteins. AtTPK1 and AtTPK2 are biochemically redundant cytosolic proteins that are similarly expressed throughout different plant tissues. The essential nature of TPKs in plant metabolism is reflected in the observation that while single gene knockouts of either AtTPK1 or AtTPK2 were viable, the double mutant possessed a seedling lethal phenotype. HPLC analysis revealed the double mutant is nearly devoid of TPP and instead accumulates the precursor of the TPK reaction, free thiamin. These results suggest that TPK activity provides the sole mechanism by which exogenous and de novo derived thiamin is converted to the enzyme cofactor TPP.
|
| 巻・号 |
65(1-2)
|
| ページ |
151-62
|
| 公開日 |
2007-9-1
|
| DOI |
10.1007/s11103-007-9205-4
|
| PMID |
17611796
|
| MeSH |
Amino Acid Sequence
Arabidopsis / enzymology*
Arabidopsis / genetics
Gene Expression Regulation, Enzymologic
Gene Expression Regulation, Plant
Isoenzymes / chemistry
Isoenzymes / genetics
Isoenzymes / metabolism
Molecular Sequence Data
Mutation / genetics
Phylogeny
Plants, Genetically Modified
Sequence Alignment
Sequence Homology
Thiamin Pyrophosphokinase / chemistry
Thiamin Pyrophosphokinase / genetics
Thiamin Pyrophosphokinase / metabolism*
Thiamine / metabolism*
|
| IF |
3.302
|
| 引用数 |
35
|
|
WOS 分野
|
PLANT SCIENCES
BIOCHEMISTRY & MOLECULAR BIOLOGY
|
| リソース情報 |
| シロイヌナズナ / 植物培養細胞・遺伝子 |
pda01225 |
