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...

A variety of cell membrane proteins become phosphorylated in their ecto-domains by cell-surface protein kinase (ecto-PK) activities, as detected in a broad spectrum of cell types. This study reports the isolation and identification of a frequent ecto-PK substrate, ecto-p120, using HeLa cells as a model. Data from MS and further biochemical and immunochemical means identified ecto-p120 as a cell...

At least eleven thylakoid proteins become phosphorylated under reducing conditions, and redox titration has identified a common midpoint potential of Em = +38 +/- 4 mV, n = 0.95 +/- 0.06. In the presence of the phosphatase inhibitor NaF (10 mM), the redox dependency of phosphorylation is found to be essentially unchanged: Em = +50 +/- 3 mV, n = 1.02 +/- 0.04. Thylakoid membranes were phosphoryl...

Amino acid sequences of nucleocapsid proteins are mostly conserved among different rhabdoviruses. The protein plays a common functional role in different RNA viruses by enwrapping the viral genomic RNA in an RNase-resistant form. Upon expression of the nucleocapsid protein alone in COS cells and in bacteria, it forms large insoluble aggregates. In this work, we have reported for the first time ...

Vasodilator-stimulated phosphoprotein (VASP) associates with virulence factors on the surface of intracellular bacteria; by binding to profilin, VASP may help direct the actin assembly that appears to drive bacterial motility.

The forkhead-associated (FHA) domain is a phosphopeptide-binding domain first identified in a group of forkhead transcription factors but is present in a wide variety of proteins from both prokaryotes and eukaryotes. In yeast and human, many proteins containing an FHA domain are found in the nucleus and involved in DNA repair, cell cycle arrest, or pre-mRNA processing. In plants, the FHA domain...