Cloning and characterization of the cDNA coding for the catalytic alpha subunit of CK2 from tobacco.
We have previously reported the participation of the protein kinase CK2 in the mechanism by which salicylic acid activates transcription of genes, such as those coding for glutathion S-transferases, in tobacco. With the purpose of further studying the participation of CK2 in this signal transduction pathway, we isolated and sequenced the cDNA from the NtCK2A gene, coding for the catalytic alpha subunit of CK2 from tobacco. The NtCK2A cDNA was isolated by screening of a tobacco cDNA library with a heterologous probe from Arabidopsis thaliana, followed by 3' RACE to obtain the 3' region. Sequence analysis of the NtCK2A cDNA showed a high level of identity between this CK2alpha protein sequence and the corresponding sequences of other plant species such as Arabidopsis and maize (92-95% identity), or those of animal species such as human and Xenopus laevis (75% identity). The expression of the NtCK2A gene in different tissues from tobacco plants was analyzed by Northern blot. High levels of expression of this gene were observed in proliferating tissues such as shoot and root apical meristems. A recombinant CK2alpha protein was obtained after expression of the NtCK2A cDNA in Escherichia coli. The ability of this recombinant CK2alpha subunit to phosphorylate casein was inhibited by heparin and stimulated by the CK2beta subunit from Xenopus laevis.
Salinas
P
P
Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago.
Bantignies
B
B
Tapia
J
J
Jordana
X
X
Holuigue
L
L
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000201:enzymology; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D047390:Casein Kinase II; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D015723:Gene Library; D006801:Humans; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics; D014981:Xenopus; D014982:Xenopus laevis; D003313:Zea mays / Q000201:enzymology
D018076:DNA, Complementary; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D004247:DNA; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases