Biochemical characterization of a 34 kDa ribonucleoprotein (p34) purified from the spinach chloroplast fraction as an effective phosphate acceptor for casein kinase II.
A 34 kDa ribonucleoprotein (p34) was purified to homogeneity from a 1.0 M KCl extract of spinach chloroplasts and characterized as an effective phosphate acceptor for casein kinase II (CK-II). The N-terminal 21 residues (W-V-A-Q-T-S-E-E-E-Q-E-G-S-T-N-A-V-L-E-G-E) of p34 were 95% identical with the sequence reported for 28RNP (plastid mRNA 3' end processing factor in chloroplast). Moreover, the findings that DNAs as well as RNAs significantly stimulate the CK-II catalyzed phosphorylation of p34 in vitro and induce its conformational change, suggest that the physiological activity of p34-bound RNA or DNA in chloroplast post-transcriptional regulation is controlled by specific p34 phosphorylation by CK-II.
Kanekatsu
M
M
Laboratory of Biology, School of Liberal Arts and Sciences, Kitasato University, Sagamihara, Japan.
Munakata
H
H
Furuzono
K
K
Ohtsuki
K
K
D000595:Amino Acid Sequence; D047390:Casein Kinase II; D002736:Chloroplasts / Q000737:chemistry*; D008969:Molecular Sequence Data; D010710:Phosphates / Q000378:metabolism; D010766:Phosphorylation; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D014675:Vegetables / Q000737:chemistry
D010710:Phosphates; D010940:Plant Proteins; D012261:Ribonucleoproteins; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases