Here we show
that all low molecular weight proteins of PSII already accumulate in the etioplast membrane fraction in darkness, whereas PsaI and PsaJ of photosystem I (PSI) represent the only low molecular weight proteins that do not accumulate in darkness. We found by BN-PAGE separation of Selleckchem MK-0518 membrane protein complexes and selective MS that the accumulation of one-helix proteins from PSII is light independent and occurs in etioplasts. In contrast, in chloroplasts isolated from light-grown plants, low molecular weight proteins were found to specifically accumulate in PSI and II complexes. Our results demonstrate how plants grown in darkness prepare for the induction of chlorophyll dependent photosystem assembly upon light perception. We anticipate that our investigation will provide the essential means for the analysis of protein assembly in any membrane utilizing low molecular weight protein subunits.”
“Though flow cytometry provides the entire distribution of cellular fluorescence (i.e., “”fluorescence profile”"), only mean fluorescence data are usually considered in studies of ligand-receptor binding. In this study,
we presented a method of the treatment of the temporal evolution of the whole fluorescence profile with a comprehensive statistical approach extended to the reversible binding case. The method was demonstrated in the study of the 1D3 IgM monoclonal antibodies binding to Fc gamma RIIIb receptors (CD16b) on neutrophils. Kinetic experiments were carried out using a FACSCalibur (Becton Dickinson, USA) flow cytometer. For each of four donors, we find more obtained learn more the distribution of the number of Fc gamma RIIIb surface receptors
for neutrophils and the rate constants per receptor: the association rate constant of (2.7 +/- 0.4) x 10(7) M(-1) min(-1), and the dissociation rate constant of (1.3 +/- 0.4) x 10(-1) min(-1). Based on the obtained values, the size of the receptor reaction site was estimated at approximately 1 nm. It was found, that cell receptors distributions differed sufficiently between donors in mean and the skewness values, whereas the coefficient of variation (i.e., the ratio of the standard deviation to the mean) did not vary significantly. (C) 2011 Elsevier. Ltd. All rights reserved.”
“Nuclear factor-kappa B (NF-kappa B) is a transcription factor involved in a wide variety of phenomena including inflammation, immune responses, and cell survival. Abnormal activation of NF-kappa B occurs in many pathological conditions, such as allergic and auto-inflammatory diseases and malignancies. As a result, the signal-induced NF-kappa B activation pathway has been extensively studied and revealed to be regulated by ubiquitination. Several types of polyubiquitin chains exist and the type of chain seems to impact how ubiquitinated proteins are regulated. Recently, different types of polyubiquitin chains, including linear (M1) and K11 chains, have been implicated in NF-kappa B activation.