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Sachiko Matsutani

Publications and source records attributed to Sachiko Matsutani.

5 recordsLinked to original sources
PubMed2006

Possible presence and role of the promoter sequence for eukaryotic RNA polymerase III in bacteria.

The bacterial repetitive sequence IS1, is a translocatable DNA segment. The internal region of IS1 acts as a cis-element to stimulate RNA synthesis from the upstream promoter. The product of the bacterial artA gene works with this cis-element to stimulate transcription. Eukaryotic genes for small RNAs and short interspersed repetitive elements (SINEs) have internal promoters, transcribed by RNA polymerase III (RNAP III). RNAP III requires the multisubunit protein factor TFIIIC in transcription initiation. TFIIIC contains the B-block binding subunit which recognizes the internal promoter. Here, I report that the eukaryotic RNAP III promoter-like sequence was found in the cis-element of bacterial IS1. Mutations in the cis-element which affect transcription were present in the RNAP III promoter-like sequence. The RNAP III promoter sequence of Alu, which is a human SINE, was cloned into Escherichia coli, and was shown to stimulate bacterial transcription like the cis-element of IS1. Furthermore, the primary structures of ArtA protein and B-block binding subunits were compared. The amino acid sequence of ArtA appeared to be similar to the N- and C-terminal regions conserved in many B-block binding subunits. Prokaryotes and eukaryotes have been thought to have inherent transcription machineries. The results shown here, however, suggest a new aspect of the evolution of the RNAP III transcription machinery.

Alu Elements↗
PubMed2006

Links between repeated sequences.

L1 and Alu elements are long and short interspersed retrotransposable elements (LINEs and SINEs) in humans, respectively. Proteins encoded in the autonomous L1 mediate retrotransposition of the nonautonomous Alu and cellular mRNAs. Alu is the only active SINE in the human genome and is derived from 7SL RNA of signal recognition particle. In the other eukaryotic genomes, various tRNA- and 5S rRNA-derived SINEs are found. Some of the tRNA- and 5S rRNA-derived SINEs have partner LINEs of which 3' sequences are similar to those of the SINEs. One of the tRNA-derived SINEs is shown to be mobilized by its partner LINE. Many copies of tRNA and 5S rRNA pseudogenes are present in the human genome. These pseudogenes may have been generated via the retrotransposition process using L1 proteins. Although there are no sequence similarities between L1 and Alu, L1 functionally links with Alu and even cellular genes, impacting on our genome shaping.

Journal Article↗
PubMed2006

[Treatment of Henoch-Schönlein purpura nephritis in children with tonsillectomy].

Henoch-Schönlein purpura nephritis (HSPN) is an important complication of Henoch-Sch6nlein purpura (HSP). Pathological findings in the kidney are similar to those for IgA nephritis, which is characterized by the deposition of IgA immune complex in the glomerular mesangium. Since a tonsillectomy is useful for IgA nephritis, this procedure holds great promise for the treatment HSPN. In the present study, we assessed the effectiveness of a tonsillectomy in children with HSPN whose conditions could not be controlled by medication, including predonisone and cyclophosphamide. Seven patients (four boys and three girls) with histologically well-defined HSPN who had undergone a tonsillectomy between 1998 and 2000 and who had been followed for more than 6 postoperative months were retrospectively examined. The age of the patients ranged between 3 and 13 years (average, 7.6 +/- 3.2 years) at the time of operation. Postoperative changes in urinary data were assessed according in the severity of the pathological findings in the kidney and the patient's clinical condition. The severity of the pathological findings in the kidney was determined based on the classification of the International Study of Kidney Disease (ISKDC) and the Index of Glomeruler Lesion (IGL). All patients examined in the present study had an ISKDC classification of over grade II. One patient had a grade IV classification, 3 had a grade III classification, and 3 had a grade II classification. The patients were placed in one of five clinical groups: (1) nephritic-nephrotic syndrome, (2) acute nephritic syndrome, (3) nephritic syndrome, (4) over 1 g/day of proteinuria without hypoalbuminemia or oedema, or 5) below 1 g/day of proteinuria with or without hematuria. One patient was classified in group 1, 1 was group classified in 2, 2 were classified in group 3, 2 were classified in group 4 and 1 was classified in group 5. The mean observation period was 74 +/- 6.4 months. The hematuria and proteinuria resolved in all patients, regardless of their preoperative pathological or clinical severity, within 12 postoperative months. During the observation period, no relapse was observed. Moreover, all medication, including steroid use, was stopped within the observation period. Therefore, a tonsillectomy was considered to be effective for the treatment of children with HSPN whose conditions cannot be controlled using medication.

Adolescent↗
PubMed2004

Similarities in transcription factor IIIC subunits that bind to the posterior regions of internal promoters for RNA polymerase III.

BACKGROUND: In eukaryotes, RNA polymerase III (RNAP III) transcribes the genes for small RNAs like tRNAs, 5S rRNA, and several viral RNAs, and short interspersed repetitive elements (SINEs). The genes for these RNAs and SINEs have internal promoters that consist of two regions. These two regions are called the A and B blocks. The multisubunit transcription factor TFIIIC is required for transcription initiation of RNAP III; in transcription of tRNAs, the B-block binding subunit of TFIIIC recognizes a promoter. Although internal promoter sequences are conserved in eukaryotes, no evidence of homology between the B-block binding subunits of vertebrates and yeasts has been reported previously. RESULTS: Here, I reported the results of PSI-BLAST searches using the B-block binding subunits of human and Shizosacchromyces pombe as queries, showing that the same Arabidopsis proteins were hit with low E-values in both searches. Comparison of the convergent iterative alignments obtained by these PSI-BLAST searches revealed that the vertebrate, yeast, and Arabidopsis proteins have similarities in their N-terminal one-third regions. In these regions, there were three domains with conserved sequence similarities, one located in the N-terminal end region. The N-terminal end region of the B-block binding subunit of Saccharomyces cerevisiae is tentatively identified as a HMG box, which is the DNA binding motif. Although I compared the alignment of the N-terminal end regions of the B-block binding subunits, and their homologs, with that of the HMG boxes, it is not clear whether they are related. CONCLUSION: Molecular phylogenetic analyses using the small subunit rRNA and ubiquitous proteins like actin and alpha-tubulin, show that fungi are more closely related to animals than either is to plants. Interestingly, the results obtained in this study show that, with respect to the B-block binding subunits of TFIIICs, animals appear to be evolutionarily closer to plants than to fungi.

Amino Acid Sequence↗