Molecular Cloning and Characterization of cDNA for a Rice Protein that Contains Seven Repetitive Segments of the Trp-Asp Forty-Amino-Acid Repeat (WD-40 Repeat)

A cDNA clone for a polypeptide that contained seven repetitivesegments of the Trp-Asp forty-amino-acid repeat (WD-40 repeat)was isolated from a cDNA library prepared from the greeningleaves of rice. The cDNA was 1,285 bp long and contained anopen reading frame that encoded a protein of 334 amino acidresidues, which was designated it RWD (rice protein containingthe WD-40 repeat). RWD exhibited greater homology to a groupof receptor for activated C-kinase (RACK), a product of auxin-regulatedgene from cultured cells (arcA) and a Chlamydomonas ßsubunit-like polypeptide (Cblp) rather than to the ßsubunits of heterotrimeric G protein complexes. The mRNA forRWD (1.3 kb) was found in all organs of rice plants, in particular,in roots. Therefore, RWD is suggested to be a protein that isexpressed constitutively. (Received September 27, 1994; Accepted February 8, 1995)     

Isolation and Characterization of a cDNA Clone of UDP-Galactose: Flavonoid 3-0-Galactosyltransferase (UF3GaT) Expressed in Vigna mungo Seedlings

Four cDNA clones were isolated from Vigna mungo seedlings bythe screening with cDNA encoding UDP-glu-cose:flavonoid 3-0-glucosyltransferase(UF3GT) of Antirrhinum majus as a probe; the product of thegene corresponding to one cDNA was more highly expressed inthe first simple leaves than in stems. Nucleotide sequence analysisrevealed 1,691 bp (including 326 bp non-reading) containingan open reading frame of 455 amino acids. The deduced aminoacid sequence showed 42% and 23% identity with those of A. majusUDP-glucose:flavonoid 3-O-glucosyltransferase (UF3GT) and Petuniahybrida UDP-rhamnose:anthocyanidin 3-0-glucoside rhamnosyltrans-ferase(RT), respectively. One region of the cDNA (amino acids 325to 387) showed similarity to ceramide UDP-galac-tosyltransferasesof mice, rats and humans. A crude extract from Escherichia coli,in which the protein was expressed from the cDNA, showed highUF3GaT activity but low UF3GT activity, and was similar in K_m,optimal pH and substrate specificity to UF3GaT from V. mungo.We conclude that we have obtained UDP-galactose:flavonoid 3-0-galactosyltransferase(UF3GaT) cDNA from V. mungo. 4 Deceased.     

Molecular Cloning and Characterization of a cDNA for the r{beta} Subunit of a G Protein from Rice

We isolated a cDNA for the rß subunit of a heterotrimericG protein from rice (Oryza sativa L. cv. Nipponbare). The aminoacid sequence deduced from the cDNA was 76% and 94% homologusto the sequences of the rß subunits from Arabidopsisand maize (AGrß1 and ZGrß1), respectively. (Received July 28, 1995; Accepted December 25, 1995)     

Cinnamyl Alcohol Dehydrogenase from Aralia cordata: Cloning of the cDNA and Expression of the Gene in Lignified Tissues

A full-length cDNA clone encoding a subunit of cinnamyl alcoholdehydrogenase (CAD) was isolated from a perennial dicot, Araliacordata. The identity of the clone was demonstrated by two criteria:(i) the amino acid sequences of peptides derived from the purifiedCAD protein of A. cordata were highly homologous to regionsof the amino acid sequence deduced from the nucleotide sequenceof the cDNA; and (ii) a fusion protein expressed from     

Expression of a Gene for a Protein Similar to HIV-1 Tat Binding Protein 1 (TBP1) in Floral Organs of Brassica rapa

A cDNA for a protein similar to human immunodeficiency virusTat binding protein was isolated from an anther cDNA libraryof Brassica rapa. RNA in situ analysis in flower buds showedthat the gene for this cDNA was specifically expressed in thetapetum and middle layer of anthers and pollen. (Received February 15, 1997; Accepted May 28, 1997)     

cDNA Cloning and Characterization of a Gibberellin-Responsive Gene in Hypocotyls of Cucumis sativus L.

A cDNA clone corresponding to a gibberellin-responsive gene(CRG16) was isolated from cucumber hypocotyls. CRG16 was deducedto encode an extremely hydrophobic protein of 65 amino acids.The deduced sequence exhibited no significant homology to otherproteins. Levels of CRG16 mRNA reflected the gibberellin-inducedelongation of cucumber hypocotyls. (Received December 16, 1995; Accepted April 22, 1996)     

Transient Increase in the Level of mRNA for a Germin-Like Protein in Leaves of the Short-Day Plant Pharbitis nil during the Photoperiodic Induction of Flowering

A cDNA corresponding to an in vivo labeled protein whose levelincreased during flower-inductive darkness in the cotyledonof the short-day plant Pharbitis nil Choisy cv. Violet was isolatedand characterized. The deduced amino-acid sequence of the protein(designated PnGLP; P. nil germin-like protein) showed homologyto that of a GLP of Sinapis alba, a leaf protein, the mRNA accumulationof which showing circadian oscillations. PnGLP mRNA was detectedspecifically in the cotyledon and leaf, in particular, in theyoung expanded cotyledon and leaf. Accumulation of PnGLP mRNAincreased transiently during flower-inductive darkness and peakedat a time that corresponded approximately to the critical nightlength. This mRNA peak was reduced by a brief exposure to redlight at the 8th hour of darkness. The level of PnGLP mRNA peakedabout 10 h from the beginning of the dark period, whereas itwas reported that the level of mRNA for GLP of a long-day plantS. alba increased about 14 h from the beginning of the lightperiod. Thus, the different time courses of accumulation ofthe mRNAs for leaf-specific GLPs appear to reflect the differencesin photoperiodic responses of each plant. (Received May 16, 1996; Accepted July 5, 1996)     

Identification of a Novel Human Gene Containing the Tetratricopeptide Repeat Domain from the Down Syndrome Region of Chromosome 21

The Down syndrome (DS) region on chromosome 21, which is responsiblefor the DS main features, has been defined by analysis of DSpatients with partial trisomy 21. Within the DS region, we constructeda 1.6-Mb P1 contig map previously. To isolate gene fragmentsfrom the 1.6-Mb region, we performed direct cDNA library screeningand exon trapping using the P1 clones and a human fetal braincDNA library, and obtained 67 cDNA fragments and 52 possibleexons. Among them, 23 cDNA fragments and 4 exons were interpretedto be derived from a single gene by localization on P1 clonesand by Northern analysis. To obtain the full-length cDNA sequence,longer cDNA clones were further screened from another humancDNA library which was enriched with longer cDNA species. Theseclones were sequenced and assembled to a sequence of 9045 bp.This transcribed sequence encodes a novel 2025 amino-acid proteincontaining tetratricopeptide repeat (TPR) motifs and thereforethe gene was designated as TPRD (a gene containing the TPR motifson the Down syndrome region). The TPR domain has been foundin a certain protein phosphatase and in other proteins involvedin the regulation of RNA synthesis or mitosis. The TPRD gene,the novel gene which was proved to be in the 1.6-Mb region andto have the interesting features described above, is a candidatefor genes responsible for the DS phenotypes.     

Molecular Cloning and Characterization of a cDNA Clone That Encodes a Cdc2 Homolog from Nicotiana tabacum

We have isolated a cDNA clone (cdc2Nt1) that encodes a homologof p34^cdc2/CDC28 kinase from tobacco (Nicotiana tabacum). Thecdc2Ntl protein showed extensive similarity to other homologsof Cdc2 from plants. Complementation studies showed that thecdc2Ntl gene was able to overcome cell cycle arrest at boththe G1/S and the G2/M transitions of cdc28^ts mutants of buddingyeast, demonstrating that the cdc2Ntl protein was able to replacethe Cdc28 kinase at both the G1/S and the G2/M transitions.Analysis of gene expression demonstrated that the cdc2Ntl genewas transcribed constitutively throughout the cell cycle butthat it was preferentially expressed in actively dividing tobaccoBY-2 cells. (Received July 13, 1995; Accepted February 15, 1996)     

Cloning of a Novel Rat Gene, DB83, That Encodes a Putative Membrane Protein

Using a partial cDNA sequence and a 5'-RACE technique, we isolateda novel cDNA from rat liver referred to as DB83. DB83 had fourhydrophobic trans-membrane domains and one N-myristoylationsite as well as multiple possible phosphorylation sites. Thedb83 gene was highly expressed in the liver and significantlyin brain, lungs and kidneys. We suggest that DB83 is a tissue-specificputative membrane protein.     

Structure and expression of a cDNA encoding zeaxanthin epoxidase, isolated from a wilt-related tomato (Lycopersicon esculentum Mill.) library

Zeaxanthin epoxldase (ZE) catalyses two early steps in the abscisicacid (ABA) biosynthetic pathway. The sequence of a cDNA cloneencoding ZE from Nicotiana plumbaginifolia was reported In 1996and represented the first DNA sequence data on an ABA biosyntheticenzyme. The N. plumbaginifolia cDNA has been used to providea heterologous probe to isolate a ZE cDNA from tomato (Lycopersiconesculentum Mill.). DNA and amino acid sequence differences areconsidered in relation to putative functional domans withinthe enzyme. The results of northern analysis in tomato are discussedin relation to the effects of water stress on ZE mRNA levels. Key words: ABA biosynthesis, zeaxanthin epoxidase, tomato     

家蝇细胞凋亡起始酶Caspase-1基因的克隆及在不同虫态的表达

为了研究Caspases家族在昆虫发育变态中的作用,通过RT-PCR扩增并结合RACE技术,克隆得到家蝇Musca domestica Caspase-1基因1条,命名为Mdom-Caspase-1（GenBank中cDNA序列号为EU854472, 氨基酸序列号为ACF71490）。该基因全长1 295 bp,阅读框序列870 bp,共编码289个氨基酸,理论分子量32.83 kDa,等电点8.67。 Mdom-Caspase-1蛋白有5个保守的半胱氨酸位点QACQG, 具有Caspase的典型特征; 整个分子呈现亲水性, 有8个区域共89个氨基酸为亲酯性, 蛋白质二级结构主要由11个α螺旋区、7个β-折叠区、17个β-转角区组成。昆虫间Caspase-1分子具有明显的保守性, Mdom-Caspase-1与黑腹果蝇Drosophila melanogaster、埃及伊蚊Aedes aegypti和致倦库蚊Culex quinquefasciatus的Caspase-1氨基酸序列相似性为65%~77%。RT-PCR半定量分析结果表明, Mdom-Caspase-1基因在家蝇各个虫态中均有表达, 但在卵期、3龄幼虫、预蛹、蛹和羽化5 d的雌虫中的表达量明显高于其他虫态。这些结果提示Caspase-1可能与昆虫发育变态关系密切, 为进一步研究昆虫Caspase-1功能、设计Caspase-1抑制剂提供了分子基础。     

Cloning and Characterization of High-CO2-Specific cDNAs from a Marine Microalga, Chlorococcum littorale, and Effect of CO2 Concentration and Iron Deficiency on the Gene Expression

Two cDNA clones exclusively induced under an extremely high-CO₂concentration (20%) were isolated from Chlorococcum littoraleby differential screening and named HCR (high-CO₂ response)1 and 2, respectively. The amino acid sequence of the proteinencoded by HCR2 exhibited homology to the gp91-phox protein,a critical component of a human phagocyte oxidoreductase, andto the yeast ferric reductases, Saccharomyces cerevisiae FRE1and FRE2 and Schizosaccharomyces pombe Frpl. The induction ofboth HCR mRNAs required extremely high-CO₂ conditions and irondeficiency, being suppressed under air conditions and by ironsufficiency, suggesting that the expression of these two HCRgenes required extremely high-CO₂ conditions and iron deficiencyin combination. The HCR2 protein was detected in the membranefractions of cells grown under conditions which would favorthe induction of HCR2-mRNA and the protein level was loweredwhen the cells were transferred from iron deficient to 10 µMFeSO₄ conditions (with 20% CO²). (Received September 10, 1997; Accepted November 14, 1997)     

Structure and expression of a cDNA encoding a putative neoxanthin cleavage enzyme (NCE), isolated from a wilt-related tomato (Lycopersicon esculentum Mill.) library

Oxidative cleavage of a 9-cis xanthophyll probably representsthe key regulatory step in abscisic acid (ABA) biosynthesis.A transposon tagged maize (Zea mays) mutant vp14, provided theoriginal DNA sequence data needed to design a VP14 fusion proteincapable of catalysing this reaction in vitro. A cDNA encodinga similar protein has now been isolated from a wilt-relatedtomato (Lycopersicon esculentum Mill.) library. The tomato cDNAand derived amino acid sequence have been compared to thoseof maize and of other enzymes catalysing broadly similar oxidativecleavage reactions. The results of Northern analysis in tomatoindicated that mRNA levels of this vp14 homologue increaseddramatically in response to water stress. Key words: ABA biosynthesis, oxidative cleavage step, tomato