Search results

1

Two intron-containing pre-tRNAs^Tyr from Triticum aestivum are efficiently processed and spliced in homologous cell-free extract

100%

Szweykowska-Kulińska Z.

Acta Biochimica Polonica

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1992

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vol. 39

|

issue 3

283-288

2

MicroRNA biogenesis: Epigenetic modifications as another layer of complexity in the microRNA expression regulation

68%

Bhat S., Jarmolowski A., Szweykowska-Kulińska Z.

|

2016

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vol. 63

|

issue 4

717-723

EN

Since their discovery, microRNAs have led to a huge shift in our understanding of the regulation of key biological processes. The discovery of epigenetic modifications that affect microRNA expression has added another layer of complexity to the already tightly controlled regulatory machinery. Modifications like uridylation, adenylation and RNA editing have been shown to have variable effects on miRNA biogenesis and action. Methylation of the N6 adenosine has been studied extensively in mRNA. Presence of the N6-methyl-adenosine (m6A) mark and its critical importance in miRNA biogenesis in animals adds to our understanding of the regulatory mechanisms, while its effect on miRNA biogenesis in plants is yet to be understood.

3

Nucleotide sequence of nuclear tRNAGly genes and tRNAGly pseudogenes from yellow lupin (Lupinus luteus): Expression ofthe tRNAGly genes in vitro and in vivo

68%

Nuc P., Nuc K., Szweykowska-Kulińska Z., Pawełkiewicz J.

Acta Biochimica Polonica

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1997

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vol. 44

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issue 2

259-274

4

Cloning and characterization of Arabidopsis thaliana AtNAP57 - a homologue of yeast pseudouridine synthase Cbf5p.

68%

Maceluch J., Kmieciak M., Szweykowska-Kulińska Z., Jarmołowski A.

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2002

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vol. 49

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issue 3

699-709

EN

Rat Nap57 and its yeast homologue Cbf5p are pseudouridine synthases involved in rRNA biogenesis, localized in the nucleolus. These proteins, together with H/ACA class of snoRNAs compose snoRNP particles, in which snoRNA guides the synthase to direct site-specific pseudouridylation of rRNA. In this paper we present an Arabidopsis thaliana protein that is highly homologous to Cbf5p (72% identity and 85% homology) and NAP57 (67% identity and 81% homology). Moreover, the plant protein has conserved structural motifs that are characteristic features of pseudouridine synthases of the TruB class. We have named the cloned and characterized protein AtNAP57 (A rabidopsis t haliana homologue of NAP57 ). AtNAP57 is a 565 amino-acid protein and its calculated molecular mass is 63 kDa. The protein is encoded by a single copy gene located on chromosome 3 of the A. thaliana genome. Interestingly, the AtNAP57 gene does not contain any introns. Mutations in the human DKC1 gene encoding dyskerin (human homologue of yeast Cbf5p and rat NAP57) cause dyskeratosis congenita a rare inherited bone marrow failure syndrome characterized by abnormal skin pigmentation, nail dystrophy and mucosal leukoplakia.

5

Arabidopsis thaliana microRNA162 level is posttranscriptionally regulated via splicing and polyadenylation site selection

68%

Barciszewska-Pacak M., Knop K., Jarmołowski A., Szweykowska-Kulińska Z.

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2016

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vol. 63

|

issue 4

811-816

EN

Arabidopsis microRNA162 (miRNA162) level regulation was studied under abiotic stresses, such as drought and salinity. The TaqMan® microRNA assay proved that A. thaliana miRNA162 level was elevated under these stresses, confirming its salt and drought responsiveness. The promoter region analyses of A. thaliana miRNA162a and b genes (MIR162a and MIR162b) identified numerous salinity and drought responsive elements. However, our results indicated that Arabidopsis MIR162a was presumably the main locus responsible for the mature ath-miRNA162 accumulation under the stresses tested, and the MIR162b was generally rather weakly expressed, both in control and under the stress conditions. The MIR162a structure was confirmed to be complex and the pri-miRNA162a hairpin structure was shown to span an alternative exon and an intron. The MIR162a transcription generated a few pri-miRNA162a splicing isoforms that could be functional and non-functional. Upon drought and salinity stresses, the regulation of the pri-miRNA162a alternative splicing pattern revealed an increase of a functional pri-miR162a isoform and a preferential distal polyA site selection under the stress conditions. Apart from the potential transcriptional regulation of the miRNA genes (MIRs) expression, the data obtained point to an essential role of posttranscriptional regulation of Arabidopsis microRNA162 level.

6

The nuclear cap-binding protein complex is not essential for nonsense-mediated mRNA decay (NMD) in plants

68%

Dzikiewicz-Krawczyk A., Piontek P., Szweykowska-Kulińska Z., Jarmołowski A.

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2008

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vol. 55

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issue 4

825-828

EN

In this study we investigated whether in plants, like in mammals, components of the nuclear cap-binding protein complex (CBC) are involved in nonsense-mediated mRNA decay (NMD). We selected several genes producing at least two alternatively spliced mRNA variants: one with a premature termination codon (PTC+) and another without it (PTC-). For each gene the PTC+/PTC- ratio was calculated using RT-PCR and direct sequencing in four Arabidopsis thaliana lines: wild type, the NMD mutant atupf3-1 and two CBC mutants: cbp20 and abh1. Whereas in the NMD mutant the ratios of PTC+/PTC- splice variants were higher than in wild-type plants, the two CBC mutants investigated showed no change in the PTC+/PTC- ratios. Our results suggest that neither CBP20 nor CBP80 is involved in NMD in A. thaliana.

7

A cell-free yellow lupin extract containing activities of pseudouridine 35 and 55 synthases

68%

Pieńkowska J., Wrzesiński J., Szweykowska-Kulińska Z.

Acta Biochimica Polonica

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1998

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vol. 45

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issue 3

745-754

8

RNA interference and its role in the regulation of eucaryotic gene expression.

68%

Szweykowska-Kulińska Z., Jarmołowski A., Figlerowicz M.

|

2003

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vol. 50

|

issue 1

217-229

EN

Several years ago it was discovered that plant transformation with a transcribed sense transgene could shut down the expression of a homologous endogenous gene. Moreover, it was shown that the introduction into the cell of dsRNA (double-stranded RNA) containing nucleotide sequence complementary to an mRNA sequence causes selective degradation of the latter and thus silencing of a specific gene. This phenomenon, called RNA interference (RNAi) was demonstrated to be present in almost all eukaryotic organisms. RNAi is also capable of silencing transposons in germ line cells and fighting RNA virus infection. Enzymes involved in this process exhibit high homology across species. Some of these enzymes are involved in other cellular processes, for instance developmental timing, suggesting strong interconnections between RNAi and other metabolic pathways. RNAi is probably an ancient mechanism that evolved to protect eukaryotic cells against invasive forms of nucleic acids.

9

The influence of polyamines on polymerase chain reaction (PCR)

59%

Fiedorow P., Szweykowska-Kulińska Z.

Acta Biochimica Polonica

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1997

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vol. 44

|

issue 1

83-87

10

Abscisic acid does not influence the subcellular distribution of the HYL1 protein from Arabidopsis thaliana

52%

Lesicka-Górecka J., Szarzyńska B., Sawczak M., Bagdiul I., Górski P., Jarmołowski A., Szweykowska-Kulińska Z.

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2008

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vol. 55

|

issue 3

517-524

EN

HYL1 is a nuclear protein involved in the processing of miRNAs but its exact function remains unknown. Arabidopsis thaliana hyl1 mutants exhibit hypersensitivity to ABA. We decided to answer the question whether ABA affects the HYL1 protein localization within the cell and show that it does not. We also studied the expression of HYL1 in different tissues and organs. In this paper we show for the first time the expression profile of the HYL1 protein using anti-HYL1 antibodies. The protein is present in seedlings and mature plants in all organs studied, with the highest amount in inflorescences. A. thaliana HYL1 protein has several repetitions of a 28-amino-acid sequence at the C-terminus that confer protein instability. Our bioinformatic analysis of HYL1 homologs in different Brassica species shows that this repetition is typical only for Arabidopsis. This may suggest a relatively late evolutionary acquisition of the C-terminal domain.

11

New intron-containing human tRNA^Leu genes

51%

Karwowska U., Szweykowska-Kulińska Z.

Acta Biochimica Polonica

|

1997

|

vol. 44

|

issue 4

791-794

Refine search results

Two intron-containing pre-tRNAs^Tyr from Triticum aestivum are efficiently processed and spliced in homologous cell-free extract

MicroRNA biogenesis: Epigenetic modifications as another layer of complexity in the microRNA expression regulation

Nucleotide sequence of nuclear tRNAGly genes and tRNAGly pseudogenes from yellow lupin (Lupinus luteus): Expression ofthe tRNAGly genes in vitro and in vivo

Cloning and characterization of Arabidopsis thaliana AtNAP57 - a homologue of yeast pseudouridine synthase Cbf5p.

Arabidopsis thaliana microRNA162 level is posttranscriptionally regulated via splicing and polyadenylation site selection

The nuclear cap-binding protein complex is not essential for nonsense-mediated mRNA decay (NMD) in plants

A cell-free yellow lupin extract containing activities of pseudouridine 35 and 55 synthases

RNA interference and its role in the regulation of eucaryotic gene expression.

The influence of polyamines on polymerase chain reaction (PCR)

Abscisic acid does not influence the subcellular distribution of the HYL1 protein from Arabidopsis thaliana

New intron-containing human tRNA^Leu genes