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Biomedical subjects

Yumin Mao

Publications and source records attributed to Yumin Mao.

105 records · Page 6Linked to original sources

Identification of a novel human DDX40gene, a new member of the DEAH-box protein family.

The DExH/D-box superfamily of RNA helicases seems to play key roles during RNA metabolism, such as pre-mRNA splicing, ribosome biogenesis, and others. We have cloned a new gene of the DEAH-box protein subgroup, designated DDX40 (DEAD/H-box polypeptide 40 gene). DDX40 contains 3656 nucleotides and codes for a putative 779-amino-acid protein. Sequence analysis of the cDNA product revealed that it contained a DEAH (Asp-Glu-Ala-His) sequence motif and other conserved motifs. The DDX40 protein shared 53% and 43% amino acid identity with human DDX8 and yeast Drh1, respectively, in the conserved region. Northern blot analysis showed that DDX40 was expressed ubiquitously in the eight tissues examined, implying a general physiological function of the protein. We speculate that, like other members of the DExH/D-box superfamily, DDX40 may play roles in pre-mRNA splicing, ribosome biogenesis and other RNA processing functions.

Amino Acid Sequence↗

Identification and characterization of AGTRAP, a human homolog of murine Angiotensin II Receptor-Associated Protein (Agtrap).

Several classes of cytoplasmic proteins have been found to interact specifically with the carboxyl-terminal cytoplasmic region of the angiotensin II type 1 (AT(1)) receptor to regulate different aspects of AT(1) receptor physiology. The murine Angiotensin II Receptor-Associated Protein (Agtrap) is a new member of them. We have recently cloned a new human gene cDNA that codes for a homolog of the murine Agtrap protein from a human fetal brain cDNA library. The deduced polypeptide product of the cDNA is 22 kDa in size, and its DNA and amino acid sequences are 85 and 77% identical to those of the mouse Agtrap gene, respectively. Hence we have named it the human Angiotensin II Receptor-Associated Protein (AGTRAP) gene. The mRNA of AGTRAP was most abundantly expressed in kidney, heart, pancreas and thyroid. Using the yeast two-hybrid screening of a human fetal brain cDNA library, we have identified a new interaction partner of the human AGTRAP protein, RACK1 (Receptor of Activated Protein C Kinase). The AGTRAP-RACK1 interaction was confirmed by GST fusion protein pull-down assays, co-immunoprecipitation and surface plasmon resonance. We suggest that the AGTRAP-RACK1 interaction may help to recruit signaling complex to the AT(1) receptor to affect AT(1) receptor signaling.

Adaptor Proteins, Signal Transducing↗

Cloning and characterization of a novel human transcription factor AP-2 beta like gene (TFAP2BL1).

The AP-2 transcription factor has been shown to play an important role in development, morphogenesis, apoptosis, cell-cycle control and has also been implicated in mammary oncogenesis. Here we report the cloning and characterization of a novel human transcription factor AP-2 like gene (TFAP2BL1), which is located on human chromosome 6p12.1-21.1. The TFAP2BL1 cDNA is 2076 base pairs in length, encoding a 452-amino acid polypeptide related to human Ap-2protein. TFAP2BL1 gene has significantly high homology to transcription factor AP-2 gene of human, mouse, chicken, sheep, fruit fly, and C. elegans at amino acid level. RT-PCR analysis shows its relatively high expression level in adult thymus, prostate, small intestine, skeletal muscle, placenta, brain, and testis tissues.

Amino Acid Sequence↗

Cloning and characterization of a novel human pantothenate kinase gene.

Pantothenate kinase (PanK) is a key regulatory enzyme in the CoA biosynthetic pathway in bacteria and mammalian cells. It catalyzes the first committed step in the universal biosynthetic pathway leading to CoA. Here we report the molecular cloning and characterization of a new human PanK gene. The gene encoded a protein of 314 amino acid residues, which share high homology to mouse pantothenate kinase (mPanK) 1 beta. Northern blot analysis revealed a transcript of the gene of 2.6 kb in human liver and kidney. The human PanK gene was located to human chromosome between 10q22.3 and 10q23.2 by bioinformatics analysis.

Amino Acid Sequence↗

NADPH-dependent GMP reductase isoenzyme of human (GMPR2). Expression, purification, and kinetic properties.

GMP reductase (EC 1.6.6.8) is the only known metabolic step by which guanine nucleotides can be converted to the pivotal precursor of both adenine and guanine nucleotides. Human GMP reductase has been previously partially purified from erythrocytes and a chromosome 6-linked cDNA has been identified to correspond for encoding human GMP reductase. Here, we reported a distinct cDNA for human GMP reductase isoenzyme isolated from a human fetal brain library, and the GenBank accession number is AF419346. The deduced protein shows 90% identity with human GMP reductase reported (named GMPR1 compared with GMPR2 of this paper) and 69% with E. coli GMP reductase. Comparison of GMPR2 cDNA sequence with human genome indicates the corresponding gene spans about 6.6kb on chromosome 14, which encodes 348 amino acid residues. Northern hybridization analysis indicates a differential and disproportionate expression of mRNAs for GMPR1 and GMPR2, suggesting the existence of distinct molecular species of GMP reductase in human. The apparent Km of GMPR2 for NADPH and GMP are 26.6 and 17.4 microM, respectively. This is the first report suggesting the existence of two distinct types of human GMP reductase molecular species, which can be used to explain the bimodal saturation curve noted with the purified human erythrocyte GMP reductase.

Amino Acid Sequence↗

Cloning and identification of a novel cDNA which may be associated with FKBP25.

A 1209 bp novel cDNA with a putative open reading frame of 627 bp that has an overlapped fragment of 527 bp with FKBP25 was isolated from a human fetal brain library. Northern Blot analysis detected a signal about 1.5 kb that suggests it is a full-length cDNA. Reverse transcription-PCR demonstrates that the transcripts are high in adult brain, testis, ovary, spleen, and fetal brain. Comparing the cDNA with the human genome database identifies a contig that reveals that the gene contains six exons and is located on human chromosome 20p11. The gene encodes a putative protein with an unknown domain conserved in many species and is similar to bacterial histidyl-tRNA synthetase, and so it is named human histidyl-tRNA-synthetase-related gene.

Amino Acid Sequence↗

Cloning, expression and characterization of a novel human VMP gene.

We report here cloning and characterization of a novel human gene, termed VMP, which is a vesicular membrane protein. RT-PCR analysis shows that VMP is expressed exclusively in brain of the 16 tissues examined, suggesting that it is a neuron-specific membrane protein. The cDNA encodes 195 amino acid with a putative molecular weight of about 24 KDa. VMP contains two putative membrane spanning domains and a hydrophilic tail homologous to the microtubule-binding domain of MAPs. So it is speculated that VMP may associated with microtubules through its C-terminal and plays an important role in vesicular organelles transport and nerve signals.

Base Sequence↗

Cloning and characterization of a novel human STAR domain containing cDNA KHDRBS2.

KHDRBS2, KH domain containing, RNA binding, signal transduction associated 2, is an RNA-binding protein that is tyrosine phosphorylated by Src during mitosis. It contains a KH domain,which is embedded in a larger conserved domain called the STAR domain. This protein has a 99% sequence identity with rat SLM-1 (the Sam68-like mammalian protein 1) and 98% sequence identity with mouse SLM-1 in its STAR domain. KHDRBS2 has the characteristic Sam68 SH2 and SH3 domain binding sites. RT-PCR analysis showed its transcript is ubiquitously expressed. The characterization of KHDRBS2 indicates it may link tyrosine kinase signaling cascades with some aspect of RNA metabolism.

Amino Acid Sequence↗

Cloning and characterization of a novel human alcohol dehydrogenase gene (ADHFe1).

There are three types of NAD(P)(+)-dependent alcohol dehydrogenase: "medium-chain" zinc-containing enzymes, "short-chain" zinc-lacking enzymes and iron-activated enzymes. Although the medium-chain family and the short-chain family have been characterized in human, the iron-activated alcohol dehydrogenase family seems to exist only in microbial organisms. We have now cloned and characterized an iron-activated alcohol dehydrogenase gene, Fe-containing alcohol dehydrogenase 1 (ADHFe1) in human. The cDNA was isolated from the human fetal brain cDNA library. It contains a long open reading frame, which is not homologous with the other alcohol dehydrogenases isoenzymes characterized in human. The hypothetical alcohol dehydrogenase does, however, show strong homology to the iron-activated alcohol dehydrogenases from microbial organisms. Northern blotting analysis only detected expression in adult liver tissue. At least two different splicing variants were screened by PCR using the multiple tissue cDNA panels as templates.

Alcohol Dehydrogenase↗

Molecular cloning, mapping and characterization of a human CK1gamma1 gene.

We isolated and sequenced a cDNA clone coding a human protein kinase CK1 (casein kinase 1) by screening a human fetal brain cDNA library. This new cDNA clone of 1756 bp contained an open reading frame, encoding a protein of 438 amino acids with a molecular weight of 50,272 Da and an isoelectric point of 9.37. The entire amino acid sequence of the novel human CK1 was 94% homologous to that of rat CK1gamma1. Northern blot analysis indicated that the human CK1gamma1 was highly expressed in the liver, skeletal muscle, heart and kidney. Furthermore, the human CK1gamma1 gene was mapped to chromosome 15q22 between STS marker D15S159 and D15S125 by polymerase chain reaction analysis of human/rodent hybrid cell panels.

Amino Acid Motifs↗

[Expression of cell adhesion molecules in acute leukemia cell].

OBJECTIVE: To investigate the role of cell adhesion molecule in the development and extramedullary infiltration (EI) of acute leukemia. METHODS: The expressions of neural cell adhesion molecule (NCAM) gene, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1) genes in 25 acute leukemia patients bone marrow cells were detected by microarray and reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: The expressions of NCAM, ICAM-1 and VCAM-1 gene were significantly higher in acute leukemia cells and leukemia cells with EI than in normal tissues and leukemia cells without EI, respectively, both by cDNA microarray and by RT-PCR. CONCLUSION: The cDNA microarray is a powerful technique in analysis of acute leukemia cells associated genes. High expressions of cell adhesion molecule genes might be correlated with leukemia pathogenesis and infiltration of acute leukemia cell.

Acute Disease↗

[Analysis of function of the 452 bp sequence proceeding the pgiB gene in Bacillus stearothermophilus].

By random mutagenesis with chemical mutagen N-methyl-N'-nitro-N-nitrosoguanidine, a shuttle promoter probe vetor mutant pPGV5 (tr65) was obtained. A single site mutation from G to T was discovered at nucleotide + 238 of kan gene encoding kanamycin nucleotidyltransferae by sequence analysis. Using the gene pheB that encodes thermostable catechol 2'3-dioxygenase from Bacillus stearothermophilus FDTP-3 as the reporter gene, a transcriptional fusion plasmid pPGVPB452 was constructed and electroportated into B. stearothermophilus. By analyzing the reporter protein, it proved that the 452 bp sequence proceeding the coding region of phosphoglucoisomerase pgiB gene from B. stearothermophilus T521, which contained a putative promoter by sequence analysis, but has no transcriptional activity in B. stearothermophilus.

Catechol 2,3-Dioxygenase↗

[Gene chip screen in allergic rhinitis and preliminary analysis of the differential expressed genes].

OBJECTIVE: To discover the etiology of allergic rhinitis(AR) at the genomic level. METHODS: Microarray analysis on a genomic scale was used to find changes in genes expression in AR. The total RNAs were isolated from nasal mucosa of AR and normal, then purified to mRNAs and were reversely transcribed to cDNAs with the incorporation of fluorescent-labeled dUTP to prepare for the hybridization probes. The genes differential expressed in AR were screened with the gene chip which contained 12,800 human genes in all 8 samples. RESULT: 734 genes were shown in differential expressed profile with 430 upregulated genes and 304 downregulated genes, and all 8 samples were 15 genes upregulated and 6 genes downregulated. The differential expressed genes involved in the functions of inflammation, immunology, neuroendocrine and signal conduct, and they had potential value in AR study. CONCLUSION: The investigation based on gene chip in researching related genes in AR afforded a new idea in studying pathogenesis of nasal allergic diseases.

DNA, Complementary↗

Molecular cloning and characterization of a novel human kinase gene, PDIK1L.

We isolated a 4301-bp cDNA from a human foetal brain cDNA library by high-throughput cDNA sequencing. It encodes a protein of 341 amino acids, which shows 69% identity with the human kinase CLIK1 (AAL99353), which was suggested to be the CLP-36 interacting kinase. Bioinformatics analysis suggests that the putative kinase may interact with PDZ and LIM domain proteins. Therefore the protein and its cDNA were named 'PDLIM1 interacting kinase 1 like' (PDIK1L; nomenclature approved by the HUGO Gene Nomenclature Committee). Ensembl Genome Browser located PDIK1L to human chromosome 1p35.3. It spans about 13.7 kb and consists of four exons and three introns. Multiple-tissue cDNA panel PCR revealed that the gene is expressed widely in human tissues: liver, kidney, pancreas, spleen, thymus and prostate. The protein appears to be localized to the nucleus.

Amino Acid Sequence↗