The catalytic subunit of protein kinase CK2 phosphorylates in vitro the movement protein of Tomato mosaic virus.
The movement protein (MP) of Tomato mosaic virus (ToMV) was reported previously by us to be phosphorylated in vitro by a cellular protein kinase(s) that exhibited several characteristics of casein kinase 2 (CK2). To characterize further this CK2-like cellular kinase, we have cloned cDNAs encoding the CK2 catalytic subunit from tobacco and compared the properties of the recombinant protein with those of the CK2-like cellular kinase. The recombinant CK2 catalytic subunit formed a complex with ToMV MP and phosphorylated it, similar to the CK2-like cellular kinase. Phosphoamino acid analyses of various mutant MPs altered near the C terminus revealed that the recombinant CK2 catalytic subunit phosphorylated serine-261, while the CK2-like cellular kinase phosphorylated both serine-261 and threonine-256. Both kinases were suggested to phosphorylate an additional serine residue(s) in regions other than the C-terminal peptide. The results are consistent with our previous prediction of involvement of CK2 in phosphorylation of ToMV MP.
Matsushita
Yasuhiko
Y
Gene Research Center, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan.
Ohshima
Mayumi
M
Gene Research Center, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan.
Yoshioka
Kuniaki
K
Gene Research Center, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan.
Nishiguchi
Masamichi
M
National Institute of Agrobiological Sciences, 2-1-2 Kan-nondai, Tsukuba, Ibaraki 305-8602, Japan.
Nyunoya
Hiroshi
H
Gene Research Center, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan.
D047390:Casein Kinase II; D020134:Catalytic Domain / Q000502:physiology*; D003001:Cloning, Molecular; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010766:Phosphorylation; D053830:Plant Viral Movement Proteins; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017898:Tobamovirus / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
D053830:Plant Viral Movement Proteins; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D005982:Glutathione Transferase; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases