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Yumin Mao

Publications and source records attributed to Yumin Mao.

At least 73 records · Page 4Linked to original sources
PubMed2004

Cloning and characterization of a novel human cDNA encoding a J-domain protein (DNAJA5) from the fetal brain.

J-domain proteins are involved in protein importing and sorting, protein translocation into the endoplasmic reticulum and interaction with hsp70, cell cycle regulation and exocytosis. During the large-scale sequencing analysis of a human fetal brain cDNA library, we isolated a cDNA clone encoding a putative 531 amino acid protein with a DnaJ domain and C2H2-type zinc finger motif, which was named as DNAJA5 (human DnaJ homology subfamily A member 5). The putative protein of DNAJA5 gene was homologous to Caenorhabditis elegans DNJ-17 (identity 33.2% similarity 45.1%). By mapping, we located DNAJA5 gene to human chromosome 5p12-5p13. The DNAJA5 gene contained at least 12 exons that spanned more than 25.6 kb of the genomic sequence. The reverse transcription-polymerase chain reaction analysis indicated that it was expressed in the human brain, placenta, kidney and pancreas. DNAJA5 might play a role in co-operating with Hsp70.

Amino Acid Sequence↗
PubMed2004

cDNA cloning, gene organization and expression analysis of human peptidylarginine deiminase type VI.

Peptidylarginine deiminase (PAD) catalyzes the post-translational modification of protein through the conversion of arginine to citrulline in the presence of calcium ions. Human, similar to rodents, has four isoforms of PAD (type I, II, III and IV/V), each of which is distinct in substrate specificity and tissue specific expression. In our large-scale sequencing project, we identified a new human PAD cDNA from a human fetal brain cDNA library. The putative protein encoded by this cDNA is designated hPADVI. Expression analysis of hPADVI showed that it is mainly expressed in adult human ovary and peripheral blood leukocytes. We conclude that hPADVI may be orthologous to mouse ePAD, basing on sequence comparison, chromosome localization and exon-intron structure analysis. PAD-mediated deimination of epithelial cell keratin resulting in cytoskeletal remodeling suggests a possible role for hPADVI in cytoskeletal reorganization in the egg and in early embryo development. This study describes a new important member of the human PAD family.

Amino Acid Sequence↗
PubMed2003

Cloning of the correct full length cDNA of NF-kappaB-repressing factor.

NF-kappaB-repression factor (NRF) is a nuclear inhibitor of NF-kappaB proteins that can silence the IFNbeta promoter. Since NRF was cloned in 1999, in-depth studies have been conducted on the biological functions of this constitutive repressor of NF-kappaB proteins. During large-scale sequencing of a human fetal brain cDNA library we isolated a novel human cDNA that proved to be a correct full-length NRF cDNA. The deduced protein contains 690 aa, and has a G-patch and an R3H domain at its C-terminus. The size of the protein is consistent with its counterparts in mouse and rat. There is considerable evidence that there are some mistakes in the NRF cDNA sequence reported by Nourbakhsh. Here we report the correct, full-length cDNA and protein sequences of NRF. Full-length NRF cDNA is 3247 bp long, contains three exons and maps to human chromosome Xq24. RT-PCR shows that NRF is widely expressed in human tissues.

Amino Acid Sequence↗
PubMed2003

Determining a detectable threshold of signal intensity in cDNA microarray based on accumulated distribution.

In microarray data mining, one of the key problems is how to handle weak signals. Based on a bent piecewise linear accumulated distribution generally found in the microarray data, a new detectable threshold finding method is proposed to filter genes with unreliable information in this paper. More reliable and reproducible data is produced for the subsequent data mining.

DNA, Complementary↗
PubMed2003

Identification of a novel human doublecortin-domain-containing gene (DCDC1) expressed mainly in testis.

Mutations in the X-linked gene doublecortex (DCX) result in lissencephaly in males or subcortical laminar heterotopia (double cortex) in females. Recently, an evolutionarily conserved doublecortin (DC) domain important for microtubule binding and microtubule polymerization was defined according to detailed sequence analysis of DCX and DCX-like proteins. Subsequently we cloned a novel human cDNA that contained a DC domain during large-scale DNA sequencing of the human fetal brain cDNA library, and termed it doublecortin-domain-containing 1 (DCDC1). According to a search against the human genome database, DCDC1 was mapped to 11p13. Expression analysis showed that DCDC1 was mainly expressed in adult testis. Furthermore, the expression level of DCDC1 in fetal brain was much higher than in adult brain.

Amino Acid Sequence↗
PubMed2003

Molecular cloning and characterization of a novel human J-domain protein gene (HDJ3) from the fetal brain.

The J-domain is believed to be part of a chaperone involved in protein folding. From a fetal brain cDNA library, we isolated a cDNA of 3249 bp encoding a novel human J-domain protein, which was named as HDJ3. The expression pattern of HDJ3 was examined by reverse transcription/polymerase chain reaction, which suggested that the transcripts were highly expressed in human pancreas and selectively expressed in human brain, lung, liver, skeletal muscle and kidney. The results also showed that a probable splice variant of HDJ3 gene might exist. The HDJ3 gene was located on human chromosome 12q13.1-12q13.2 and consisted of seven exons spanning 8593 bp of the human genome. PSORT analysis indicated that the HDJ3 gene contained a transmembrane domain. The putative protein of the HDJ3 gene was highly homologous to rat dopamine-receptor-interacting protein, suggesting that it was a novel member of the molecular chaperone family and functionally related to dopamine signal transduction.

Amino Acid Sequence↗
PubMed2003

Isolation and identification of a novel cDNA that encodes human yrdC protein.

In the course of detecting the interaction protein of RBBP10 by yeast two-hybridization, we isolated a novel cDNA that encodes a putative human protein with yrdC domain. It is named human yrdC protein. Because the cDNA contains an open reading fragment (ORF) without a 5' in- frame stop codon, 5' RACE and 3' RACE were proceeded to produce the full-length cDNA. An 1825 bp cDNA was isolated from human placenta, which encodes a putative protein of 279 amino acids. The protein contains a sua5-yciO-yrdC domain. Blast analysis against the human genome database of Genbank revealed that the gene contains five exons, and assigned the gene to human chromosome 1p34.2. A transcript about 2.5 kb is ubiquitously expressed in human tissues. The gene is highly conserved during evolution.

Amino Acid Sequence↗
PubMed2003

Molecular cloning and characterization of a novel dual-specificity phosphatase18 gene from human fetal brain.

Dual-specificity protein phosphatases (DSPs), a new family of protein tyrosine phosphatases (PTPs), are characterized by the ability to dephosphorylate both phospho-tyrosyl and phospho-seryl/threonyl residues. It has been known that most of the enzymes play important roles in the regulation of mitogenic signal transduction and control the cell cycle in response to extracellular stimuli. In this study, a novel human DSP gene named Dual-specificity Phosphatase18 (DUSP18) was isolated by large-scale sequencing analysis of a human fetal brain cDNA library. DUSP18 is localized at Chromosome 22 q12.1. Its cDNA is 2450 base pairs in length, encoding a 188-amino acid polypeptide in which a DSP motif but not a CH2 domain is included. RT-PCR revealed that the DUSP18 was widely expressed in different tissues. GST-DUSP18 fusion protein showed distinctive phosphatase activity toward p-nitrophenyl phosphate (pNPP), as well as oligopeptides containing pThr and pTyr, indicating that DUSP18 is a protein phosphatase with dual substrate specificity. The optimal condition for the reaction was pH 6.0 and 55 degrees C. Addition of Mn(2+) ions was able to enhance the enzyme activity while the activity was strongly inhibited by iodoaretic acid. Mutations in selected sites showed the importance of Asp-73, Cys-104, Arg-110 and Ser-111 in phosphatase activity of DUSP18.

Amino Acid Sequence↗
PubMed2003

Isolation and characterization of a novel human NM23-H1B gene, a different transcript of NM23-H1.

The NM23 gene is a conspicuous metastasis-suppressor gene. Eight human genes of the NM23/nucleoside diphosphate kinase family have been discovered. From our large cDNA cloning and sequencing project, we cloned a different transcript ( NM23-H1B) of human NM23-H1 from 18-week-old human fetal brain. The 987-bp cDNA encodes a protein of 177 amino acid residues. Compared with NM23H1, the cDNA contained an additional NH(2)-terminal region (25 amino acid residues). It was mapped to chromosome 17q21.3 using bioinformatics analysis, which shows that the second exon does not exist in NM23-H1. The expression pattern of NM23-H1B showed that it was ubiquitously expressed in normal tissues (15 tissues except colon) at different levels. Our data also indicated that the expression of the transcript in tumors related to tumor differentiation: in poorly differentiated breast carcinoma GI-101, pancreatic adenocarcinoma GI-103, and undifferentiated ovarian carcinoma GI-102, there was no expression. In poorly differentiated lung carcinoma LX-1, lung carcinoma GI-117, the expression level was very low. The transcript band in well-differentiated colon adenocarcinoma CX-1 was significantly higher than that in poorly differentiated colon adenocarcinoma GI-112. A high transcription level was also found in grade IV prostatic adenocarcinoma PC3.

Adenocarcinoma↗
PubMed2003

Molecular cloning and characterization of the protein 4.1O gene, a novel member of the protein 4.1 family with focal expression in ovary.

Protein 4.1 is an important structural protein that is expressed in erythroid and in a variety of nonerythroid tissues. In mammalian erythrocytes, it plays a key role in regulating the physical properties of mechanical stability and deformability in membranes by stabilizing the spectrin-actin interaction. The protein 4.1 family mainly comprises 4.1R, 4.1G (general type), 4.1B (brain type), and 4.1N (neuron type). We identified a novel human 4.1 ( 4.1O) gene that is 2312 bp in length and encodes a protein of 553 amino acid residues. The protein shared homology with mouse protein 4.1B (identity 38%, similarity 55%) with a FERM domain. The expression pattern of the human 4.1O gene in 16 tissues showed that there was a transcript only in ovary, whereas in the remaining 15 tissues, specific bands of the transcript could not be detected. In eight human fetal tissues, the specific bands of the transcript could be detected in skeletal muscle, with lower levels detected in thymus and brain. The 4.1O gene consists of 14 exons and 13 introns and was mapped to Chromosome 9q21-9q22 by bioinformatics analysis.

Amino Acid Sequence↗
PubMed2003

Identification of a novel human angiopoietin-like gene expressed mainly in heart.

The angiopoietins are an important family of growth factors specific for vascular endothelium. Most of them bind to the TIE2 receptor and are related to regulation of angiogenesis. During large-scale DNA sequencing of the human fetal brain cDNA library, we cloned a novel human angiopoietin-like cDNA and termed it human angiopoietin-like 5 ( ANGPTL5). Like other members of the angiopoietin family, ANGPTL5-deduced protein also has an N-terminal cleavable signal peptide, a predicted coiled-coil domain, and a fibrinogen-like domain. The search against the human genome database indicated that ANGPTL5 maps to 11q22. Expression analysis of ANGPTL5 shows that it is mainly expressed in adult human heart.

Amino Acid Sequence↗
PubMed2003

Molecular cloning and characterization of a novel human protein phosphatase, LMW-DSP3.

Reversible phosphorylation is recognized to be a major mechanism for the control of intracellular events in eukaryotic cells. From a human fetal brain cDNA library, we isolated a cDNA clone encoding a novel dual specificity protein phosphatase, which showed 88% identity with previously reported mouse LMW-DSP3 at the amino acid level. The deduced protein had a single dual-specificity phosphatase catalytic domain, and lacked a cdc25 homology domain. LMW-DSP3 was expressed in the heart, lung, liver, and pancreas, and the expression level in the pancreas was highest. The LMW-DSP3 gene was located in human chromosome 2q32, and consisted of five exons spanning 21kb of human genomic DNA. LMW-DSP3 fused to GST showed phosphatase activity towards p-nitrophenyl phosphate which was optimal at pH 7.0 and 40 degrees C, and the activity was enhanced by Ca(2+) and Mn(2+). The phosphatase activity of LMW-DSP3 was inhibited by orthovanate. LMW-DSP3 showed phosphatase activity toward oligopeptides containing pSer/Thr and pTyr, indicating that LMW-DSP3 is a protein phosphatase with dual substrate specificity.

Amino Acid Sequence↗
PubMed2003

Cloning and identification of a novel cDNA coding thioredoxin-related transmembrane protein 2.

Thioredoxin plays an important role in various cellular processes through redox regulation. Here we report the molecular cloning and characterization of one member of the thioredoxin superfamily, designated as TMX2. The TMX2 cDNA consists of 1644 nucleotides and contains an open reading frame encoding a protein of 372 amino acids with a predicted molecular mass of 42.5 kDa and an isoelectric point of 8.94. The TMX2 protein may possess an N-terminal signal peptide, a potential transmembrane domain, an Myb DNA-binding domain repeat signature, a thioredoxin consensus pattern, an endoplasmic reticulum (ER) membrane retention signal (KKXX-like motif), and a dileucine motif in the tail. Northern blot analysis shows it is widely expressed in human tissues.

Amino Acid Motifs↗
PubMed2003

Cloning, expression and genomic structure of a novel human GNB2L1 gene, which encodes a receptor of activated protein kinase C (RACK).

During a large-scale screen of a human fetal brain cDNA library, a novel human gene GNB2L1 encoding a novel RACK (receptor of activated protein kinase C) protein was isolated and sequenced. The cDNA is 1142 bp long and has a predicted open reading frame encoding 316 aa. The predicted protein shows higher similarity to rat RACK1 and many RACK proteins of different organisms including Drosophila, C. elegans, mouse, rat, human, C. fasciculata, zebrafish, A. thaliana, S. cerevisiae and so on, suggesting it is conserved during evolution. The gene was mapped to human chromosome 5q35.3, the telomer position of chromosome 5q, in which the disease gene for early-onset primary congenital lymphedema was mapped. Also, 5q35.3 is a frequently reported location for cytogenetic and molecular abnormalities in renal cell carcinomas. The gene has 8 exons and 7 introns. It is expressed ubiquitously in many human tissues detected by northern blot analysis and RT-PCR.

Chromosome Mapping↗
PubMed2003

Cloning and expression of a novel human C5orf12 gene*, a member of the TMS_TDE family.

We report here cloning and characterization of a novel human gene, termed C5orf12, which is a putative membrane protein belonging to the TMS_TDE family. The cDNA encodes 423 amino acid with a putative molecular weight of about 47 KDa. Secondary structure prediction showed that C5orf12 contained 10 putative transmembrane helices, which has high identity with other family members. We performed RT-PCR to examine its expression pattern. The result showed that C5orf12 was highly expressed in placenta, skeletal muscle, spleen, thymus, testis and peripheral leukocyte while expressed weakly in heart and liver. C5orf12 has high identity with the rat TPO1, so we speculate that C5orf12 may also have a role in the brain development.

Amino Acid Sequence↗
PubMed2003

Molecular cloning and characterization of a novel human hydroxysteroid dehydrogenase-like 2 (HSDL2) cDNA from fetal brain.

Hydroxysteroid dehydrogenases (HSDs) are responsible for the biosynthesis of steroid hormones and play a crucial role in mammalian physiology and development. By large-scale sequencing analysis of a human fetal brain cDNA library, we isolated a novel human hydroxysteroid dehydrogenase-like cDNA (HSDL2). This cDNA is 3211 bp in length, encoding a 418-amino-acid polypeptide, which contains a typical motif for NAD(P)+-binding (TGxxxGxG), an SDR active site motif (S-Y-K) and a sterol carrier protein domain. HSDL2 shows high similarity with the homologues in the mouse and fruit fly. The HSDL2 gene is mapped to chromosome 9q32 and contains 11 exons. RT-PCR analysis shows that the HSDL2 gene is widely expressed in human tissues and the expression levels in liver, kidney, prostate, testis, and ovary are relatively high.

Amino Acid Motifs↗
PubMed2003

Isolation and characterization of a human putative receptor protein kinase cDNA STYK1.

Protein kinases (PKs) represent a well studied but most diverse protein superfamily. The covalent, reversible linkage of phosphate to serine, threonine, and tyrosine residues of substrate proteins by protein kinases is probably ubiquitous cellular mechanism for regulation of physiological processes. It is known to us that most signaling pathways impinge at some point on protein kinases. Here we report a human putative receptor protein kinase cDNA STYK1. The STYK1 cDNA is 2749 base pairs in length and contains an open reading frame encoding 422 amino acids. The STYK1 gene is mapped to human chromosome 12p13 and 11 exons were found. RT-PCR showed that STYK1 is widely expressed in human tissues.

Amino Acid Sequence↗