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S K Tsui

Publications and source records attributed to S K Tsui.

At least 37 records · Page 2Linked to original sources

Developmental regulation of 14-3-3 epsilon isoform in rat heart.

Human heart cDNA sequencing yielded a cDNA clone that is similar in DNA and amino acid sequences to that of mouse 14-3-3 epsilon isoform. The 6xHis-tagged H1433 epsilon recombinant protein was expressed in Escherichia coli and its size was approximately 30 kDa. From Northern blot results with human multiple tissues, human skeletal muscle was found to have the highest level of h1433 epsilon mRNA expression, whereas Northern blots of human cancer cell lines detected the highest mRNA level of h1433 epsilon in colorectal adenocarcinoma SW480. The protein expression level of h1433 epsilon and Raf-1 is found to be regulated coordinately during rat heart development, and their protein expression was highest from 14.5 to 16.5 days postcoitum.

14-3-3 Proteins↗

Mapping of the human cysteine-rich intestinal protein gene CRIP1 to the human chromosomal segment 7q11.23.

We report here on the mapping of a cDNA encoding for human cysteine-rich heart protein (HCRHP), a counterpart of the murine cysteine-rich intestinal protein CRIP. By somatic cell hybrid analysis and radiation hybrid mapping, we have located the gene CRIP1 (HGMW-approved symbol) on the subcentromeric region of the q arm of human chromosome 7, flanking a deletion associated with Williams syndrome.

Animals↗

Chromosomal mapping of a skeletal muscle specific LIM-only protein FHL3 to the distal end of the short arm of human chromosome 1.

Four-and-a-half LIM domain proteins (FHL) possess four tandem repeats of LIM domain and an extra zinc finger. FHL family LIM proteins are unique when compared with other LIM-only proteins because they possess an odd number of zinc fingers. In this study, the tissue distribution and chromosomal mapping of skeletal muscle LIM protein FHL3 were reported. When the FHL3 cDNA probe was used to hybridize with poly-(A) RNA of various human tissues, a very strong signal was detected in skeletal muscle, and virtually no signal could be detected in heart, brain, placenta, lung, liver, kidney and pancreas. Using radiation hybrid technique, FHL3 gene was mapped to the distal end of the short arm of chromosome 1 (123.26 cR from the top of the Chr1 linkage group) and this region (near 1p34) is related to several human malignancies.

Animals↗

A genome-based resource for molecular cardiovascular medicine: toward a compendium of cardiovascular genes.

BACKGROUND: Large-scale partial sequencing of cDNA libraries to generate expressed sequence tags (ESTs) is an effective means of discovering novel genes and characterizing transcription patterns in different tissues. To catalogue the identities and expression levels of genes in the cardiovascular system, we initiated large-scale sequencing and analysis of human cardiac cDNA libraries. METHODS AND RESULTS: Using automated DNA sequencing, we generated 43,285 ESTs from human heart cDNA libraries. An additional 41,619 ESTs were retrieved from public databases, for a total of 84,904 ESTs representing more than 26 million nucleotides of raw cDNA sequence data from 13 independent cardiovascular system-based cDNA libraries. Of these, 55% matched to known genes in the Genbank/EMBL/DDBJ databases, 33% matched only to other ESTs, and 12% did not match to any known sequences (designated cardiovascular system-based ESTs, or CVbESTs). ESTs that matched to known genes were classified according to function, allowing for detection of differences in general transcription patterns between various tissues and developmental stages of the cardiovascular system. In silico Northern analysis of known gene matches identified widely expressed cardiovascular genes as well as genes putatively exhibiting greater tissue specificity or developmental stage specificity. More detailed analysis identified 48 genes potentially overexpressed in cardiac hypertrophy, at least 10 of which were previously documented as differentially expressed. Computer-based chromosomal localizations of 1048 cardiac ESTs were performed to further assist in the search for disease-related genes. CONCLUSIONS: These data represent the most extensive compilation of cardiovascular gene expression information to date. They further demonstrate the untapped potential of genome research for investigating questions related to cardiovascular biology and represent a first-generation genome-based resource for molecular cardiovascular medicine.

Blotting, Northern↗

Mapping of the human ribosomal large subunit protein gene RPL29 to human chromosome 3q29-qter.

The human ribosomal protein L29, which we reported previously, was subsequently shown to have the same nucleotide sequence as that of cell surface heparin/heparan sulfate-binding protein, designated HP/HS interacting protein. A polymerase chain reaction-based strategy was used to distinguish the functional intron-containing gene RPL29 (HGMW-approved symbol) from multiple pseudogenes. By somatic cell hybrid analysis, radiation hybrid mapping, and fluorescence in situ hybridization, we have located RPL29 on the telomeric region of the q arm of chromosome 3. RPL29 is the most distal marker of the long armof chromosome 3. Of the human ribosomal protein genes mapped, RPL29 is the shortest distance from another ribosomal protein gene marker, RPL35 a which has also been mapped to the 3q29-qter region.

Chromosome Mapping↗

Isolation, characterization, and chromosomal mapping of a novel cDNA clone encoding human selenium binding protein.

We have isolated the full-length human 56 kDa selenium binding protein (hSP56) cDNA clone, which is the human homolog of mouse 56 kDa selenium binding protein. The cDNA is 1,668 bp long and has an open reading frame encoding 472 amino acids. The calculated molecular weight is 52.25 kDa and the estimated isoelectric point is 6.13. Using Northern blot hybridization, we found that this 56 kDa selenium binding protein is expressed in mouse heart with an intermediate level between those found in liver/lung/kidney and intestine. We have also successfully expressed hSP56 in Escherichia coli using the expression vector-pAED4. The hSP56 gene is located at human chromosome 1q21-22).

Amino Acid Sequence↗

A novel cDNA encoding a human homologue of ribosomal protein L29.

During the large scale partial sequencing of human heart cDNA clones, a novel clone which is very similar to the rat ribosomal protein L29 in both DNA and amino acid sequences was found. The cDNA encodes a protein with a deduced molecular weight of 17751 (159 aa). It shows 80.4% homology to protein L29 from the large ribosomal subunit of rat and is related to yeast YL43. The putative protein was named human ribosomal protein L29 (hRPL29). hRPL29 has a large excess of basic residues over acidic ones. The large amount of charged residues makes the protein very hydrophilic and the protein has a deduced pI of 12.16. Internal repeats have been characterised in many ribosomal proteins and a tandem repeat of KAKAKAKA was found to be unique to hRPL29. Analysis of gene organisation by Southern blotting shows that of the approximate 10 copies of hrpL29, all but one are pseudogenes. Northern analysis indicated that the mRNA that encodes human L29 is approx. 800 base pairs in length. An intron of hrpL29 has also been cloned and sequenced by polymerase chain reaction using human genomic DNA as the template.

Amino Acid Sequence↗

Identification of a cDNA encoding 6-phosphogluconate dehydrogenase from a human heart cDNA library.

A full-length cDNA clone for human 6-phosphogluconate dehydrogenase (PGD) was isolated from a human adult heart cDNA library. The clone encoded an open reading frame of 483 amino acids. When the amino acid sequences of human PGD and sheep PGD were aligned, 94.2% identity between these two proteins was found. Its calculated molecular weight is 53,149 daltons. The predicted isoelectric point is 6.85. When the secondary structure of human PGD was examined by the PROSIS software, 36% alpha-helix and 9% beta-sheet were found.

Adult↗

Primary structures and sequence analysis of human ribosomal proteins L39 and S27.

We report here the primary structures and sequence analysis of the human ribosomal protein L39 (hRPL39) and S27 (hRPS27). The hRPL39 cDNA is 352 bp in size encoding a predicted protein of 51 amino acids. The region KRRHWRRTKL near the carboxyl end is conserved between human, rat, maize, C. elegans and yeast. The hRPS27 cDNA is 321 bp in size encoding a deduced protein of 84 amino acids. When the deduced amino acid sequence of hRPS27 was compared with that of rat ribosomal protein S27 and human metalloproteinstimulin-1 (MPS-1), identity levels of 96.4% and 100% were obtained respectively. A potential polyadenylation signal AACAAA is found in the MPS-1 cDNA but the more frequently used AATAAA sequence is present in the hRPS27 cDNA. The carboxyl-terminal cysteine arrangement in hRPS27 is similar to the family of C4 zinc finger DNA-binding proteins.

Amino Acid Sequence↗

A novel cDNA encoding for a LIM domain protein located at human chromosome 14q32 as a candidate for leukemic translocation.

A full-length cDNA clone encoding a zinc finger protein was isolated and sequenced. This full-length clone consists of 728 bp and has a predicted open reading frame (ORF) encoding 208 amino acids. The ORF of this polypeptide codes for the human cysteine-rich protein 2 (HCRP2) and has an amino acid sequence that is 92.8% identical to its rat homolog (RCRP2). HCRP2 was mapped to chromosome 14q32, which is a hot spot of translocation in tumor development, by fluorescent in situ hybridization (FISH).

Amino Acid Sequence↗

Isolation and characterization of a cDNA that codes for a LIM-containing protein which is developmentally regulated in heart.

During our human heart cDNA sequencing project, we have obtained a novel cDNA clone which is very similar in DNA and amino acid sequences to a rat/mouse cysteine-rich intestinal protein (1). Sequence analysis has shown that this human cysteine-rich heart protein (hCRHP) is a protein of 77 amino acids and possesses a LIM motif which is considered to be able to bind zinc. Northern blot analyses have shown that its mRNA level in rat heart is regulated developmentally. We have expressed hCRHP in E. coli using pAED4 as the vector and the cDNA was engineered so that the authentic protein is produced. The protein was partially purified and was shown to be a basic protein.

Adult↗

Combined effects of a metabolic inhibitor (gabaculine) and an uptake inhibitor (ketamine) on the gamma-aminobutyrate system in mouse brain.

The intramuscular administration of a gamma-aminobutyrate-alpha-oxoglutarate aminotransferase (GABA-T) inhibitor, gabaculine, to mice resulted in significant increases in GABA content and decreases in the content of aspartate, glutamate, and glutamine in the nerve endings (synaptosomes). These effects were ameliorated by the concurrent administration of the GABA uptake inhibitor ketamine. A major cause of these effects was the gabaculine-induced inhibition of GABA-T activity and the lessening of this inhibition by ketamine. The latter phenomenon was not due to a direct action of ketamine on the enzyme, nor to an interaction between gabaculine and ketamine. Rather, it appeared that ketamine might be interfering with the transport of gabaculine into the cellular structures. The anticonvulsant action of the GABA-T inhibitor and the GABA uptake inhibitor together was little different from that of the GABA-T inhibitor alone.

4-Aminobutyrate Transaminase↗

Interactions of di-n-propylacetate, gabaculine, and aminooxyacetic acid: anticonvulsant activity and the gamma-aminobutyrate system.

Di-n-propylacetate (DPA), aminooxyacetic acid (AOAA), and gabaculine were administered alone or in combination to Swiss mice. Six hours after administration of the drugs the anticonvulsant action (against isonicotinic acid hydrazide-induced seizures) of AOAA and DPA combined was less than that of AOAA alone. The cause of this phenomenon appeared to be an interaction between DPA and AOAA with respect to inhibition of GABA-T activity, resulting in a long-term diminished inhibition by AOAA, which in turn led to a lessening of the AOAA-induced elevation in the GABA content of nerve endings (synaptosomes). An excellent correlation was observed between the delay in onset of seizures and the elevation of synaptosomal GABA content.

Acetates↗

Synthesis and evaluation of benzylfluorenyl and 1-arylethyl quaternary ammonium salts for antimicrobial and antineoplastic activities.

A number of substituted benzyldimethyl-9-fluorenylammonium bromides (II) and 9-benzylfluorenyl-9-trimethylammonium bromides (IV) were synthesized and examined for antimicrobial and anticancer activites. Series IV showed greater antimicrobial activity than Series II while some corresponding acyclic fluorene analogs were bereft of antimicrobial activities. Significant antineoplastic activity was not found in Series II and IIV. Representative fluorenes subjected to a preliminary screen for various pharmacological activities revealed marked anti-inflammatory and analgesic properties coupled with some antihistaminic activities. The acyclic quaternary ammonium compounds demonstrated substantial pressor activites.

Animals↗

Characterization of tissue-specific LIM domain protein (FHL1C) which is an alternatively spliced isoform of a human LIM-only protein (FHL1).

We have cloned and characterized another alternatively spliced isoform of the human four-and-a-half LIM domain protein 1 (FHL1), designated FHL1C. FHL1C contains a single zinc finger and two tandem repeats of LIM domains at the N-terminus followed by a putative RBP-J binding region at the C-terminus. FHL1C shares the same N-terminal two-and-a-half LIM domains with FHL1 but different C-terminal protein sequences. Due to the absence of the exon 4 in FHL1C, there is a frame-shift in the 3' coding region. Sequence analysis indicated that FHL1C is the human homolog of murine KyoT2. The Northern blot and RT-PCR results revealed that FHL1 is widely expressed in human tissues, including skeletal muscle and heart at a high level, albeit as a relatively low abundance transcript in brain, placenta, lung, liver, kidney, pancreas, and testis. In contrast, FHL1C is specifically expressed in testis, skeletal muscle, and heart at a relatively low level compared with FHL1. The expression of FHL1C transcripts was also seen in aorta, left atrium, left, and right ventricles of human heart at low level. Immunoblot analysis using affinity-purified anti-FHL1C antipeptide antibodies confirmed a 20 kDa protein of FHL1C in human skeletal muscle and heart. Unlike FHL1B, which is another FHL1 isoform recently reported by our group and localized predominantly in the nucleus [Lee et al., 1999], FHL1C is localized both in the nucleus and cytoplasm of mammalian cell.

Alternative Splicing↗

Molecular cloning and characterization of a RING-H2 finger protein, ANAPC11, the human homolog of yeast Apc11p.

Yeast Apc11p together with Rbx1 and Roc2/SAG define a new class of RING-H2 fingers in a superfamily of E3 ubiquitin ligases. The human homolog of Apc11p, ANAPC11 was identified during a large-scale partial sequencing of a human liver cancer cDNA library and partial characterization was performed. This 514 bp full-length cDNA has a predicted open reading frame (ORF) encoding 84 amino acids. The ORF codes for ANAPC11, the human anaphase promoting complex subunit 11 (yeast APC11 homolog), which possesses a RING-H2 finger motif and exhibits sequence similarity to subunits of E3 ubiquitin ligase complexes. In Northern blot hybridization with poly(A) RNA of various human tissues using radio-labelled ANAPC11 cDNA probe, we found strong signals detected in skeletal muscle and heart; moderate signals detected in brain, kidney, and liver; and detectable but low signals in colon, thymus, spleen, small intestine, placenta, lung, and peripheral blood leukocyte. The ANAPC11 gene is located at the human chromosome 17q25. ANAPC11 is distributed diffusely in the cytoplasm and nucleus with discrete accumulation in granular structures in all the cell lines (AML 12, HepG2, and C2C12) transfected. Expression level of ANAPC11 is found higher in certain types of cancer determined in the RNA dot blot experiment.

Anaphase-Promoting Complex-Cyclosome↗