The oxidative burst is likely the most rapid defense response mounted by a plant under pathogen attack, and the generated oxidant species may be essential to several subsequent defense responses. In our effort to characterize the signal-transduction pathways leading to rapid H2O2/O2- biosynthesis, we have examined the role of protein phosphorylation in this resistance mechanism. K-252a and stau...

Several groups have reported that okadaic acid (OA) and some other tight-binding protein phosphatase inhibitors including microcystin-LR (MCLR), calyculin-A and tautomycin prevent each other from binding to protein phosphatase 2A (PP2A). In this paper, we have introduced an improved procedure for examining to what extent the affinity of an enzyme for a labelled tight-binding ligand is reduced b...

We studied the cellular phosphatase inhibitors okadaic acid (OKA), calyculin A, and microcystin on the epithelial sodium channel (ENaC) in A6 renal cells. OKA increased the amiloride-sensitive current after approximately 30 min with maximal stimulation at 1-2 h. Fluctuation analysis of cell-attached patches containing a large number of ENaC yielded power spectra with corner frequencies in untre...

Interactions between cells and the surrounding matrix are critical to the development and engineering of tissues. We have investigated the role of cell-derived traction forces in the assembly of extracellular matrix using what we believe is a novel assay that allows for simultaneous measurement of traction forces and fibronectin fibril growth at discrete cell-matrix attachment sites. NIH3T3 cel...

The protein phosphatase inhibitors okadaic acid and calyculin A at moderate concentrations induced three types of apoptotic promyelocytic leukemia cell death, distinct with respect to ultrastructure and polynucleotide fragmentation. Calyculin A at higher concentrations (> 50 nM) induced a non-apoptotic death type with high ATP and pronounced micromitochondriosis. This suggests that protein phos...

MutLα, a heterodimer consisting of MLH1 and PMS2, is key player in the DNA mismatch repair (MMR) system great importance to correct incorporation errors that occur during replication. Previously, we identified posttranslational phosphorylation at amino acid position serine 477 can switch off MMR activity vitro. We also found mutation prevented phosphorylation. Since involved numerous MMR-indepe...

OBJECTIVE In the present study an attempt was made to estimate coefficients of dose response curves for PCC aberrations induced by CalyculinA and Okadaic acid, using 60Co gamma radiation and 8 MeV pulsed electron beam for biodosimetry application. MATERIALS AND METHODS The modified method outlined by Puig et al. 2013 was used to conduct Calyculin A and Okadaic acid induced PCC assay in human ...