The beta subunit of chloroplast ATP synthase (CF0CF1-ATPase) is phosphorylated by casein kinase II.
We studied a phosphate acceptor for casein kinase II (CK-II) in chloroplasts, and found a 56 kDa protein (p56) as an acceptor, which was partially purified from the stroma of spinach chloroplasts. The N-terminal amino acid sequence of p56 was identical with that of the beta subunit of chloroplast ATP synthase (CF0CF1-ATPase). In addition, the recombinant beta subunit of CF1 was phosphorylated when the subunit was incubated with CK-II. These results suggest that the beta subunit of CF1 is a substrate protein of CK-II in the chloroplast.
Laboratory of Biology, Kitasato University, Sagamihara, Japan.
M
M
Kanekatsu
H
H
Saito
K
K
Motohashi
T
T
Hisabori
D000595:Amino Acid Sequence; D047390:Casein Kinase II; D002736:Chloroplasts / Q000201:enzymology*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D018724:Spinacia oleracea
D011994:Recombinant Proteins; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D006180:Proton-Translocating ATPases