It has recently been shown that anthracycline antibiotic-resistant tumor cells are less responsive to daunorubicin-stimulated B23 nucleolar phosphoprotein translocation than drug-sensitive cells. Since cyclosporin A and verapamil reverse primary acquired and secondary cross-resistance to daunorubicin, we investigated the effect of these agents on nucleolar B23 translocation in sensitive and res...

Phosphorylated signaling molecules are biomarkers of cancer pathophysiology and resistance to therapy, but because phosphoprotein analytes are often labile, poorly controlled clinical laboratory practices could prevent translation of research findings in this area from the bench to the bedside. We therefore compared multiple biomarker and phosphoprotein immunohistochemistry (IHC) results in 23 ...

A rapid, manyfold increase in phosphorylation of cardiac microsomes consisting primarily of sarcoplasmic reticulum was seen when these membranes were incubated in the presence of a bovine cardiac adenosine 3’:5’-monophosphate (cyclic AMP)-dependent protein kinase (protein kinase) and cyclic AMP. Over 85 % of the 3*P associated with membrane protein under similar conditions was identified cs pho...

During ATP hydrolysis the K+-translocating Kdp-ATPase from Escherichia coli forms a phosphorylated intermediate as part of the catalytic cycle. The influence of effectors (K+, Na+, Mg2+, ATP, ADP) and inhibitors (vanadate, N-ethylmaleimide, bafilomycin A1) on the phosphointermediate level and on the ATPase activity was analyzed in purified wild-type enzyme (apparent Km = 10 microM) and a KdpA m...

1. On incubating cerebral-cortex slices at 37 degrees in an oxygenated medium marked changes resulted in the subcellular distribution of proteins and phosphoproteins in the tissue. The protein content of the nuclear fraction more than doubled, whereas the yields of microsomal and supernatant proteins were both markedly decreased. The amount of phosphoprotein/mg. of protein decreased in the micr...

Borna disease virus (BDV) is unique among the non-segmented negative-strand RNA viruses of animals and man because it transcribes and replicates its genome in the nucleus of the infected cell. It has recently been discovered that BDV expresses a gene product of 87 amino acids, the p10 protein, from an open reading frame that overlaps with the gene encoding the viral p24 phosphoprotein. In addit...