ABSTRACT
Using ssDNA-cellulose column chromatography, a 34 kDa ribonucleoprotein (p34) has been purified from a 0.4 M KCl crude extract of spinach chloroplasts as an effective phosphate acceptor for casein kinase II (CK-II) in vitro. Monomeric and oligomeric CK-IIs were copurified with p34 by the column chromatography and the kinases were separated from p34 by means of Mono Q column chromatography. It was found that (i) the purified p34 (pI 4.9) was phosphorylated specifically by CK-II in vitro; and (ii) similar polypeptides, such as p35 (pI 4.7) and p39 (pI 4.9) in maize and p33 (pI 4.7) in liverwort, were detected as ssDNA-binding chloroplast proteins phosphorylated by CK-II in vitro. The findings suggest that (i) RNPs that function as phosphate acceptors for CK-II exist commonly in chloroplasts among plant cells; and (ii) the physiological activity of RNPs is regulated by their specific phosphorylation by CK-II in chloroplasts.
Subject(s)
Phosphates/metabolism , Plant Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Ribonucleoproteins/metabolism , Casein Kinase II , Chloroplasts/chemistry , Chromatography, Agarose , DNA, Single-Stranded/chemistry , Peptides/metabolism , Phosphorylation , Plant Proteins/isolation & purification , Plants/chemistry , Ribonucleoproteins/isolation & purification , Spinacia oleracea/chemistry , Substrate Specificity , Zea mays/chemistryABSTRACT
Primary coronary artery dissection occurring as a spontaneous event and not associated with trauma due to catheter manipulation is rare. We recently experienced (a case of) a 52-year-old man with primary artery dissection. He was admitted to our hospital with severe chest pain as his chief complaint on September 6, 1988. Electrocardiography and laboratory data showed acute inferior myocardial infarction. He was treated with medication and underwent coronary angiograms on October 3, 1988. Right coronary angiogram revealed an intimal flap and false lumen. But right coronary angiograms 6 months after the onset of myocardial infarction revealed progression of stenosis but no intimal flap, and coronary spasm was not evoked after acetylcholine administration. Primary coronary artery dissection has been reported since Pretty's first description of it in 1931. The majority of earlier cases were diagnosed at autopsy, but recently reports of survivors have been increasing due to the progress in and popularization of coronary angiographic technics. This case is the 46th case of primary coronary dissection found by coronary angiography. So it is not extremely rare. In our case the involved artery was the right coronary artery. In survivors, right coronary artery dissection is more frequent than left, because the area supplied by the right coronary artery is smaller than the area supplied by the left one. Although in our case coronary artery stenosis progressed, after a long term resolution of dissection may occur. There are a few cases in which resolution of dissection occurred naturally.(ABSTRACT TRUNCATED AT 250 WORDS)
