Identification and molecular cloning of two homologues of protein phosphatase X from Arabidopsis thaliana

Pérez-Callejón, Encarna; Casamayor, Antonio; Pujol, Gemma; Clua, Elisabet; Ferrer, Albert; Ariño, Joaquı́n

doi:10.1007/bf00042351

Cited by 24 publications

(15 citation statements)

References 38 publications

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“…The genome of Arabidopsis contains at least five genes encoding the catalytic subunit of PP2A and m R N A produced by each gene can be detected in all Arabidopsis organs [2,4,19,23]. Taken together with the gene expression data presented here, indicating that both B and all three A regulatory subunit genes are expressed in all tissues, our results indicate that within a single Arabidopsis cell a number of different PP2A isoform subunit associations can occur.…”

Section: N T G M V G S S N S S R S S I a G G E G A N S E D S G T E M supporting

confidence: 56%

“…We were interested in determining if there is coordinate expression among the subunits of PP2A in Arabidopsis. While the pattern of expression of the catalytic subunit genes in this organism has been well documented [2,4,19], no reports were available regarding the accumulation of mRNAs from its three A regulatory subunit genes. In an effort to prepare gene specific probes from the three A regulatory subunit genes for northern blot experiments we isolated c D N A sequences representing each of the three genes.…”

Section: N T G M V G S S N S S R S S I a G G E G A N S E D S G T E M mentioning

confidence: 99%

“…In Arabidopsis the catalytic subunit of PP2A is encoded by at least five genes, each of which appears to be expressed in all tissues albeit at different levels [2,4,19,23]. The A regulatory subunit of PP2A is encoded by at least three genes in Arabidopsis [21], and to date a single cDNA encoding the 55 kDa B regulatory subunit of PP2A has been isolated from this organism [20].…”

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confidence: 99%

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Characterization of DNA sequences encoding a novel isoform of the 55 kDa B regulatory subunit of the type 2A protein serine/threonine phosphatase of Arabidopsis thaliana

et al. 1996

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We have identified a novel gene (AtB beta) encoding a previously uncharacterized isoform of the B regulatory subunit of the type 2A serine/threonine protein phosphatase (PP2A) of Arabidopsis, and show that mRNA derived from the AtB beta gene accumulates in all Arabidopsis organs. In addition, we examined the expression of the three genes encoding the A regulatory subunit of Arabidopsis PP2A and show these genes are expressed in all organs as well. Taken together, our results suggest a myriad of PP2A subunit combinations, possibly with distinct substrate specificities, may occur within each Arabidopsis cell.

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Section: N T G M V G S S N S S R S S I a G G E G A N S E D S G T E M supporting

confidence: 56%

Section: N T G M V G S S N S S R S S I a G G E G A N S E D S G T E M mentioning

confidence: 99%

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confidence: 99%

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Characterization of DNA sequences encoding a novel isoform of the 55 kDa B regulatory subunit of the type 2A protein serine/threonine phosphatase of Arabidopsis thaliana

et al. 1996

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“…On the other hand, it is possible that the conserved regions function in the regulation of the activity of PP2Ac or related phosphatases, an effect that has not yet been examined. Future experiments will be aimed at deciphering the role of these conserved residues/regions in the interaction and effect of TAP46 with PP2A and the known plant homologs of PP4 (Pérez-Callejó n et al, 1993).…”

Section: Discussionmentioning

confidence: 99%

The Arabidopsis Homolog of Yeast TAP42 and Mammalian α4 Binds to the Catalytic Subunit of Protein Phosphatase 2A and Is Induced by Chilling

1999

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Type 2A serine/threonine protein phosphatases (PP2A) have been implicated as important mediators of a number of plant growth and developmental processes. In an effort to identify plant PP2A substrates and/or regulators, we performed a yeast two-hybrid screen using an Arabidopsis PP2A catalytic subunit cDNA as bait. All true positives identified by this screen were derived from the same gene, which we have named TAP46 (2A phosphatase associated protein of 46 kD). The TAP46 gene appears to be a single-copy gene and is expressed in all Arabidopsis organs. Transcripts derived from this gene are induced by chilling treatment but not by heat or anaerobic stress. Immunoprecipitation assays using antibodies generated to a peptide spanning amino acids 356 to 366 of TAP46 indicate that TAP46 is associated with a type 2A protein phosphatase in vivo. A search of the database identified TAP46 as a homolog of Saccharomyces cerevisiae TAP42 and mammalian ␣4. These two proteins are known to bind to the catalytic subunit of PP2A and to function in the target-of-rapamycin signaling pathway. Our results identify TAP46 as a plant PP2A-associated protein, with a possible function in the chilling response, and suggest that a target-of-rapamycin-like signaling pathway may exist in plants.

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“…In some cases, these novel phosphatases have been found in a variety of species and share with PP-Ic and PP-2Ac the characteristic of being extremely conserved in their primary structure. For instance, this is the situation for PPX, a PP-2Ac-related protein that has been cloned from mammals [4,5], Drosophila [5] and higher plants [6].…”

Section: Introductionmentioning

confidence: 99%

Biochemical characterization of recombinant yeast PPZ1, a protein phosphatase involved in salt tolerance

Posas¹,

Stalmans²,

Ariño³

1995

FEBS Letters

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The Saccharomyces cerevisiae gene PPZ1 codes for a 692-residues protein that shows in its carboxyl-terminal half about 60% identity with the catalytic subunit of mammafian and yeast protein phosphatase-1 and that is involved in salt homeostasis. The complete PPZ1 protein has been succesfully expressed as a soluble glutathione-S-transferase fusion protein. The recombinant protein, after purification by a single affinity chromatography step, displayed phosphatase activity towards a number of substrates, including myefin basic protein, histone 2A and casein, but was ineffective in dephosphorylating glycogen phosphorylase. It was also active towards p-nitrophenylphosphate. The activity was severalfold increased by the presence of Mn 2+ ions and by limited trypsinolysis. The enzyme was inhibited by okadaic acid and microcystin-LR at concentrations comparable to what is found for type 1 protein phosphatase although it was much less sensitive to inhibitor-2. The recombinant protein was phosphorylated in vitro by cAMP-dependent protein kinase, protein kinase C and casein kinase-2. Phosphorylation affected preferentially sites located in the amino-terminal half of the protein and did not alter the activity of the phosphatase.

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Identification and molecular cloning of two homologues of protein phosphatase X from Arabidopsis thaliana

Cited by 24 publications

References 38 publications

Characterization of DNA sequences encoding a novel isoform of the 55 kDa B regulatory subunit of the type 2A protein serine/threonine phosphatase of Arabidopsis thaliana

Characterization of DNA sequences encoding a novel isoform of the 55 kDa B regulatory subunit of the type 2A protein serine/threonine phosphatase of Arabidopsis thaliana

The Arabidopsis Homolog of Yeast TAP42 and Mammalian α4 Binds to the Catalytic Subunit of Protein Phosphatase 2A and Is Induced by Chilling

Biochemical characterization of recombinant yeast PPZ1, a protein phosphatase involved in salt tolerance

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