Arabidopsis PASTICCINO2 is an antiphosphatase involved in regulation of cyclin-dependent kinase A

Laboratoire de Biologie Cellulaire, Institut National de la Recherche Agronomique, F-78026 Versailles Cedex, France.
The Plant Cell (Impact Factor: 9.34). 07/2006; 18(6):1426-37. DOI: 10.1105/tpc.105.040485
Source: PubMed

ABSTRACT PASTICCINO2 (PAS2), a member of the protein Tyr phosphatase-like family, is conserved among all eukaryotes and is characterized by a mutated catalytic site. The cellular functions of the Tyr phosphatase-like proteins are still unknown, even if they are essential in yeast and mammals. Here, we demonstrate that PAS2 interacts with a cyclin-dependent kinase (CDK) that is phosphorylated on Tyr and not with its unphosphorylated isoform. Phosphorylation of the conserved regulatory Tyr-15 is involved in the binding of CDK to PAS2. Loss of the PAS2 function dephosphorylated Arabidopsis thaliana CDKA;1 and upregulated its kinase activity. In accordance with its role as a negative regulator of the cell cycle, overexpression of PAS2 slowed down cell division in suspension cell cultures at the G2-to-M transition and early mitosis and inhibited Arabidopsis seedling growth. The latter was accompanied by altered leaf development and accelerated cotyledon senescence. PAS2 was localized in the cytoplasm of dividing cells but moved into the nucleus upon cell differentiation, suggesting that the balance between cell division and differentiation is regulated through the interaction between CDKA;1 and the antiphosphatase PAS2.

34 Reads
  • Source
    • "So far, only a limited number of studies have applied DRAQ5™, mostly in animal cells. However, DRAQ5™ was used as a fluorescent dye to stain the nuclear DNA of root hairs in Arabidopsis plants and to examine the physiological conditions of microorganisms during fermentation processes (Da Costa et al., 2006; Herrero et al., 2006). As compared with other fluorescent DNA dyes, it has many advantages, such as a low level of photobleaching and a wide range of red excitation/emission ranges that is compatible with other fluorescent proteins including GFP, cyan fluorescent protein, and yellow fluorescent protein (Martin et al., 2005). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The bacteria B1-9 that was isolated from the rhizosphere of the green onion could promote growth of pepper, cucumber, tomato, and melon plants. In particular, pepper yield after B1-9 treatment on the seedling was increased about 3 times higher than that of control plants in a field experiment. Partial 16S rDNA sequences revealed that B1-9 belongs to the genus Pantoea ananatis. Pathogenecity tests showed non-pathogenic on kimchi cabbage, carrot, and onion. The functional characterization study demonstrated B1-9's ability to function in phosphate solubilization, sulfur oxidation, nitrogen fixation, and indole-3-acetic acid production. To trace colonization patterns of B1-9 in pepper plant tissues, we used fluorescent dye, which stains the DNAs of bacteria and plant cells. A large number of B1-9 cells were found on the surfaces of roots and stems as well as in guard cells. Furthermore, several colonized B1-9 cells resided in inner cortical plant cells. Treatment of rhizosphere regions with strain B1-9 can result in efficient colonization of plants and promote plant growth from the seedling to mature plant stage. In summary, strain B1-9 can be successfully applied in the pepper plantation because of its high colonization capacity in plant tissues, as well as properties that promote efficient plant growth.
    The plant pathology journal 09/2012; 28(3). DOI:10.5423/PPJ.OA.02.2012.0026 · 0.72 Impact Factor
  • Source
    • "Downregulation of biological processes involved in cell differentiation may seem contrary to initiation of shoot growth. However, some of the transcripts identified in this biological process (ESM-4; 0 vs. 72 down) such as PASTICCINO2 (PAS2), slowed down cell division at the G2-to-M transition and early mitosis in cell suspensions and inhibited Arabidopsis seedling growth when overexpressed (Da Costa et al. 2006). Thus, downregulation of some transcripts included in cell differentiation would be consistent with induction of cell division/differentiation required for new shoot growth. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Dormancy in underground vegetative buds of Canada thistle, an herbaceous perennial weed, allows escape from current control methods and contributes to its invasive nature. In this study, ~65 % of root sections obtained from greenhouse propagated Canada thistle produced new vegetative shoots by 14 days post-sectioning. RNA samples obtained from sectioned roots incubated 0, 24, 48, and 72 h at 25°C under 16:8 h light-dark conditions were used to construct four MID-tagged cDNA libraries. Analysis of in silico data obtained using Roche 454 GS-FLX pyrosequencing technologies identified molecular networks associated with paradormancy release in underground vegetative buds of Canada thistle. Sequencing of two replicate plates produced ~2.5 million ESTs with an average read length of 362 bases. These ESTs assembled into 67358 unique sequences (21777 contigs and 45581 singlets) and annotation against the Arabidopsis database identified 15232 unigenes. Among the 15232 unigenes, we identified processes enriched with transcripts involved in plant hormone signaling networks. To follow-up on these results, we examined hormone profiles in roots, which identified changes in abscisic acid (ABA) and ABA metabolites, auxins, and cytokinins post-sectioning. Transcriptome and hormone profiling data suggest that interaction between auxin- and ABA-signaling regulate paradormancy maintenance and release in underground adventitious buds of Canada thistle. Our proposed model shows that sectioning-induced changes in polar auxin transport alters ABA metabolism and signaling, which further impacts gibberellic acid signaling involving interactions between ABA and FUSCA3. Here we report that reduced auxin and ABA-signaling, in conjunction with increased cytokinin biosynthesis post-sectioning supports a model where interactions among hormones drives molecular networks leading to cell division, differentiation, and vegetative outgrowth.
    Functional & Integrative Genomics 05/2012; 12(3):515-31. DOI:10.1007/s10142-012-0280-5 · 2.48 Impact Factor
  • Source
    • "Phosphorylated CDKA is inactive and is activated by dephosphorylation by the phosphatase CDC25. In pasticcino2 mutants, CDKA;1 is dephosphorylated (presumably by CDC25) and activated (Da Costa et al., 2006). It is highly unlikely that EGG-4 and EGG-5 inhibit MBK-2 by a similar mechanism, since tyrosinephosphorylated MBK-2 is active, and EGG-4 inhibits MBK-2 in vitro in the absence of any other proteins. "
    [Show abstract] [Hide abstract]
    ABSTRACT: DYRKs are kinases that self-activate in vitro by autophosphorylation of a YTY motif in the kinase domain, but their regulation in vivo is not well understood. In C. elegans zygotes, MBK-2/DYRK phosphorylates oocyte proteins at the end of the meiotic divisions to promote the oocyte-to-embryo transition. Here we demonstrate that MBK-2 is under both positive and negative regulation during the transition. MBK-2 is activated during oocyte maturation by CDK-1-dependent phosphorylation of serine 68, a residue outside of the kinase domain required for full activity in vivo. The pseudotyrosine phosphatases EGG-4 and EGG-5 sequester activated MBK-2 until the meiotic divisions by binding to the YTY motif and inhibiting MBK-2's kinase activity directly, using a mixed-inhibition mechanism that does not involve tyrosine dephosphorylation. Our findings link cell-cycle progression to MBK-2/DYRK activation and the oocyte-to-embryo transition.
    Cell 10/2009; 139(3):560-72. DOI:10.1016/j.cell.2009.08.047 · 32.24 Impact Factor
Show more