Distinctive features of plant protein kinase CK2

In plants, protein kinase CK2 is involved in different processes that control many aspects of metabolism and development. In mammals and yeast the enzyme is a heterotretamer composed of two types of subunits. During years the subunit composition of the maize protein kinase CK2 enzyme has been a source of controversy. We have recently characterized the maize holoenzyme subunits. Our results show that multiple catalytic and regulatory subunits are expressed in maize and are able to specifically interact with other α and β subunits suggesting a high level of heterogeneity in the typical heterotetrameric structure. Here, we summarize data available on plant CK2 enzymes, in order to clarify the distinctive features and functions of plant protein kinase CK2.This work was supported by grant BIO2000-1562. M.R. was supported by grant 200 1 TDO C000 12 from Generalitat de Catalunya (Spain).Peer reviewe

Adoptive transfer of regulatory T cells.

<p>Naïve mice that were transferred with different cells, were subsequently sensitized with CMP and CT, and finally challenged with CMP_ig (n = 5/group). <b>A</b>, Transfer of <i>in vitro</i>-differentiated Treg. Sorted naïve CD4⁺CD25^- spleen cells were stimulated with a-CD3/a-CD28, IL-2 and TGF-β for 5 days. CD25⁺FoxP3⁺ cells gated on CD4⁺ lymphocytes were quantified (histogram) by flow cytometry and transferred to naïve receptor mice. <b>B,</b> Skin test, symptoms scored following the oral challenge and serum CMP-specific IgE in receptor mice. a) Control mice: naïve mice only received PBS_iv; b) Control mice: naïve mice received PBS_iv and were sensitized; c) naïve mice received differentiated-Treg and were sensitized. <b>C,</b><i>In vivo</i>-induced Treg in mice that were orally given daily dose of CMP and then sensitized (CMP_prev). As control, donor mice received daily dose of PBS_ig and then were sensitized (PBS_prev). MLN cells were isolated from donor mice and FoxP3⁺ cells (gated from CD4⁺CD25⁺ lymphocytes) were evaluated and quantified by flow cytometry. <b>D</b>, CD25 depletion was performed on MLN cells and evaluated by flow cytometry. Depleted and not depleted cells were adoptively transferred to receptor mice, which were then sensitized. <b>E</b>, Skin test, symptoms scored following the oral challenge and serum CMP-specific IgE in receptor animals. a) Control mice: naïve recipient mice received PBS_iv and then were sensitized; b) Control mice: receptor mice that received MLN cells depleted with a-CD25 isolated from donor PBS_prev animals and then were sensitized; c) Receptor mice that received MLN cells depleted with a-CD25 isolated from donor CMP_prev animals and then were sensitized; d) Receptor mice that received MLN cells from PBS_prev animals treated with isotype control antibody and then were sensitized; e) Receptor mice that received MLN cells from CMP_prev animals treated with isotype control antibody and then were sensitized. Results are representative of two independent experiments with similar results. Two-way ANOVA was used because all the data had normal distribution and equal variances <i>***P</i><0.001, <i>**P</i><0.01, <i>*P</i><0.05.</p