Reference "Molecular cloning of the cDNA for the catalytic subunit of plant DNA polymerase alpha and its cell-cycle dependent expression"

Reference ID

5160

Title

Molecular cloning of the cDNA for the catalytic subunit of plant DNA polymerase alpha and its cell-cycle dependent expression

Source

Genes to cells : devoted to molecular & cellular mechanisms, 1997, vol. 2, pp. 695-709

Authors (6)

Yokoi-M	Ito-M
Izumi-M	Miyazawa-H
Nakai-H	Hanaoka-F

Abstract

BACKGROUND: DNA polymerase alpha has been studied in considerable detail in
yeast and animals. Genetic and biochemical analyses reveal that this enzyme is
composed of a heterotetramer and is necessary for replicon initiation and primer
synthesis in lagging strand synthesis. In spite of the fact that modes of DNA
replication in plants seem to be similar to those in other eukaryotes, very
little is known about the biochemical components that participate in DNA
replication of plants, including DNA polymerases. RESULTS: Using a 561-base pair
DNA fragment, obtained by polymerase chain reaction amplification from a rice
cDNA library as a probe, we isolated and sequenced a cDNA homologous to the cDNA
for the catalytic subunit of rice DNA polymerase alpha. The encoded polypeptide
has extensive homology with the catalytic subunit of DNA polymerase alpha from
several species. Furthermore, when the cDNA was expressed in eukaryotic
transcription/translation systems, the protein products showed DNA polymerase
activity which was inhibited by a monoclonal antibody specific for DNA
polymerase alpha. Using RNA gel blot analysis, we found that the levels of mRNA
of the catalytic subunit of this enzyme is regulated during the cell-cycle in
plant cells. CONCLUSION: This is the first report which describes the cDNA
cloning of plant DNA polymerase. We conclude that the principal features of the
DNA polymerase alpha catalytic subunit are conserved in plants.