Biomedical subjects

W Qian

Publications and source records attributed to W Qian.

At least 19 recordsLinked to original sources

PubMed2006

Introgression of genomic components from Chinese Brassica rapa contributes to widening the genetic diversity in rapeseed (B. napus L.), with emphasis on the evolution of Chinese rapeseed.

In spite of its short history of being an oil crop in China, the Chinese semi-winter rapeseed (Brassica napus L., 2n = 38, AACC) has been improved rapidly by intentional introgression of genomic components from Chinese B. rapa (2n = 20, AA). As a result, the Chinese semi-winter rapeseed has diversified genetically from the spring and winter rapeseed grown in the other regions such as Europe and North America. The objectives of this study were to investigate the roles of the introgression of the genomic components from the Chinese B. rapa in widening the genetic diversity of rapeseed and to verify the role of this introgression in the evolution of the Chinese rapeseed. Ten lines of the new type of rapeseed, which were produced by introgression of Chinese B. rapa to Chinese normal rapeseed, were compared for genetic diversity using amplified fragment length polymorphism (AFLP) with three groups of 35 lines of the normal rapeseed, including 9 semi-winter rapeseed lines from China, 9 winter rapeseed lines from Europe and 17 spring rapeseed lines from Northern Europe, Canada and Australia. Analysis of 799 polymorphic fragments revealed that within the groups, the new type rapeseed had the highest genetic diversity, followed by the semi-winter normal rapeseed from China. Spring and winter rapeseed had the lowest genetic diversity. Among the groups, the new type rapeseed group had the largest average genetic distance to the other three groups. Principal component analysis and cluster analysis, however, could not separate the new type rapeseed group from Chinese normal rapeseed group. Our data suggested that the introgression of Chinese B. rapa could significantly diversify the genetic basis of the rapeseed and play an important role in the evolution of Chinese rapeseed. The use of new genetic variation for the exploitation of heterosis in Brassica hybrid breeding is discussed.

Brassica napus↗

PubMed2006

A phase III trial comparing CHOP to PMitCEBO with or without G-CSF in patients aged 60 plus with aggressive non-Hodgkin's lymphoma.

The management of older patients with aggressive non-Hodgkin's lymphoma presents a challenge to the physician. Age is a poor prognostic indicator, due to reduced ability to tolerate and maintain dose-intensive chemotherapy. Generally, older patients demonstrate a lower response rate, reduced survival and increased toxicity, although the majority of large randomised trials exclude older patients. This randomised trial was conducted in patients 60 years or over to compare CHOP (cyclophosphamide 750 mg m(-2), doxorubicin 50 mg m(-2), vincristine 1.4 mg m(-2), prednisolone 100 mg) with PMitCEBO (mitoxantrone 7 mg m(-2), cyclophosphamide 300 mg m(-2), etoposide 150 mg m(-2), vincristine 1.4 mg m(-2), bleomycin 10 mg m(-2) and prednisolone 50 mg). Due to the myelosuppressive nature of these regimens, patients were also randomised to the addition of G-CSF. The formal results of this trial with long-term follow-up are now reported. Data were analysed to assess efficacy and toxicity. Overall response rate was 84% in the CHOP arm and 83% in the PMitCEBO arm, with overall response rates of 83% for the use of G-CSF and 84% for no G-CSF. At median 44 months follow-up, there was no significant difference in failure-free, progression-free or overall survival between the CHOP and PMitCEBO arms. At 3 years, the actuarial failure-free survival was 44% in CHOP recipients and 42% in PMitCEBO recipients and the 3-year actuarial overall survival was 46% and 45% respectively. There was no significant difference in the failure-free, progression-free or overall survival with the addition of G-CSF.

Age Factors↗

PubMed2006

Analysis of the CDR3 region of alpha/beta T-cell receptors (TCRs) and TCR BD gene double-stranded recombination signal sequence breaks end in peripheral blood mononuclear cells of T-lineage acute lymphoblastic leukemia.

Recently, numerous reports have highlighted the restriction of the CDR3 length of T-cell receptor (TCR) beta chain in T-cells infiltrating solid tumors and hematological malignancies. However, these studies ignored the restriction of CDR3 length of TCR alpha chain and few of them attempted to reveal the mechanisms of the oligo-clonal expansion of T cells in the tumors. The primary aims of this study were twofold to: (i) analyze the CDR3 length of TCR alpha and beta chain in peripheral blood mononuclear cells of T-lineage acute lymphoblastic leukemia (T-ALL); and (ii) discover the relationship between the clonality of T cells and the process of TCR rearrangement in peripheral T cells. To this end, we investigated the TCR BV and TCR AV family spectratypes of two T-ALL patients and healthy controls using the immunoscope spectratyping technique. We found that the spectratypes exhibited a Gaussian distribution in healthy controls. However, the TCR repertoires of the two patients were highly restricted in the number of different TCR BV and TCR AV family members present. Furthermore, we found that the peripheral blood mononuclear cells (PBMC) of two T-ALL patients had the recombination signal sequence (RSS) 5'- and 3'-breaks end in the TCR BD2 gene using a specialized ligation-mediated polymerase chain reaction, implying the ongoing recombination of the TCR beta gene. Analysis of the particular CDR3 length of TCR alpha/beta T cells might be helpful for further study of the individualized therapy of T-ALL. This information will also be helpful in exploring new immunological pathogenesis and facilitating the design of a T-ALL vaccine, as well as in improving our understanding of healthy human T-cell development.

Adolescent↗

PubMed2006

Efficacy and efficiency of gastric electrical stimulation with short pulses in the treatment of vasopressin-induced emetic responses in dogs.

The aim of this study was to determine the most effective and efficient anti-emetic parameters of short-pulse gastric electrical stimulation (GES) in dogs. Seven female beagle dogs implanted with four pairs of gastric electrodes were studied in eight randomized sessions (saline, vasopressin, and six GES sessions with different parameters). Each session consisted of four 20-min recordings of gastric slow waves and symptoms. In sessions 1 and 2, saline and vasopressin, respectively, were infused during the second 20-min period. The protocol of the other six sessions was the same as session 2 except that GES was continuously applied. It was found that: (1) vasopressin induced gastric dysrhythmia and emetic response (P < 0.01, anova); (2) short-pulse GES with a frequency of 14 or 40 Hz and pulse width of 0.1 or 0.3 ms, but not 0.6 ms was able to reduce symptoms induced by vasopressin; (3) short-pulse GES with a pulse width of 0.3 ms was the most effective in preventing vasopressin-induced symptoms; (4) none of the tested GES methods improved vasopressin-induced gastric dysrhythmia. We conclude that vasopressin induces gastric dysrhythmia and symptoms. Short-pulse GES with a pulse width of 0.3 ms and frequency of 14 Hz is most effective and efficient in preventing vasopressin-induced emetic responses in dogs.

Animals↗

PubMed2005

Intersubgenomic heterosis in seed yield potential observed in a new type of Brassica napus introgressed with partial Brassica rapa genome.

This paper reports the observation on the intersubgenomic heterosis for seed yield among hybrids between natural Brassica napus (A(n)A(n)C(n)C(n)) and a new type of B. napus with introgressions of genomic components of Brassica rapa (A(r)A(r)). This B. napus was selected from the progeny of B. napus x B. rapa and (B. napus x B. rapa) x B. rapa based on extensive phenotypic and cytological observation. Among the 129 studied partial intersubgenomic hybrids, which were obtained by randomly crossing 13 lines of the new type of B. napus in F(3) or BC(1)F(3) to 27 cultivars of B. napus from different regions as tester lines, about 90% of combinations exceeded the yield of their respective tester lines, whereas about 75% and 25% of combinations surpassed two elite Chinese cultivars, respectively. This strong heterosis was further confirmed by reevaluating 2 out of the 129 combinations in a successive year and by surveying hybrids between 20 lines of the new type of B. napus in BC(1)F(5) and its parental B. napus in two locations. Some DNA segments from B. rapa were identified with significant effects on seed yield and yield components of the new type of B. napus in BC(1)F(5) and intersubgenomic hybrids in positive or negative direction. It seems that the genomic components introgressed from B. rapa contributed to improvement of seed yield of rapeseed.

Analysis of Variance↗

PubMed2005

Reproduction and cytogenetic characterization of interspecific hybrids derived from crosses between Brassica carinata and B. rapa.

The tri-genomic hybrid (ABC, 2n=27) between Brassica carinata (BBCC, 2n=34) and B. rapa (AA, 2n=20) is a unique material for studying genome relationships among Brassica species and a valuable bridge for transferring desirable characteristics from one species to the other within the genus Brassica. The crossability between B. carinata and B. rapa was varied with the cultivar of B. rapa. Hybrid pollen mother cells (PMCs), confirmed by morphological observation and molecular marker assay, could be grouped into 20 classes on the basis of chromosome pairing configurations. More than 30% of the PMCs had nine or more bivalents. Genomic in situ hybridization confirmed that two of the bivalents most likely belonged to the B genome. Nearly one-half of the PMCs had trivalents (0-2) and quadrivalents (0-2), which revealed partial homology among the A, B, and C genomes and suggested that there is a good possibility to transfer genes by means of recombination among the three genomes. The advantages of using the tri-genomic hybrids as bridge material for breeding new types of B. napus are discussed.

Brassica↗

PubMed2005

Gemcitabine plus carboplatin versus mitomycin, ifosfamide, and cisplatin in patients with stage IIIB or IV non-small-cell lung cancer: a phase III randomized study of the London Lung Cancer Group.

PURPOSE: This phase III randomized trial compared two chemotherapy regimens, gemcitabine plus carboplatin and mitomycin, ifosfamide, and cisplatin, in chemotherapy-naive patients with advanced non-small-cell lung cancer (NSCLC). The regimens were compared with regard to effects on survival, response rates, toxicity, and quality of life. PATIENTS AND METHODS: Eligible patients had previously untreated stage IIIB or IV NSCLC suitable for cisplatin-based chemotherapy. Randomly assigned patients were to receive four cycles, each at 3-week intervals, of carboplatin area under the curve of 5 on day 1 plus gemcitabine 1,200 mg/m(2) on days 1 and 8 (GCa) or mitomycin 6 mg/m(2), ifosfamide 3g/m(2), and cisplatin 50 mg/m(2) on day 1 (MIC). RESULTS: Between February 1999 and August 2001, 422 patients (GCa, n = 212; MIC, n = 210) were randomly assigned in the United Kingdom. The majority of patients received the intended four cycles (GCa, 64%; MIC, 61%). There was a significant survival advantage for GCa compared with MIC (hazard ratio, 0.76; 95% CI, 0.61 to 0. 93; P = .008). Median survival was 10 months with GCa and 7.6 months with MIC (difference, 2.4 months; 95% CI, 1.0 to 4.0), and 1-year survival was 40% with GCa and 30% with MIC (difference, 10%; 95% CI, 3% to 18%). Overall response rates were similar (42% for GCa v 41% for MIC; P = .84). More thrombocytopenia occurred with GCa (P = .03), but this was not associated with increased hospital admission or fatality. GCa caused less nausea, vomiting, constipation, and alopecia and was associated with fewer admissions for administration and better quality of life. CONCLUSION: In patients with advanced NSCLC, GCa chemotherapy was shown to be a better-tolerated treatment that conferred a survival advantage over MIC.

Adult↗

PubMed2005

Interfacial interaction of tartaric acid with hydroxyapatite and enamel.

The purpose of this study was to investigate the interfacial interaction of tartaric acid with hydroxyapatite and enamel. Hydroxyapatite particles were mixed with 15% (w/v) alcohol-aqueous (1:1) solution of tartaric acid for 72 h. After the mixture, the filtrate was separated from the solid. The filtrate, the solid, hydroxyapatite, and tartaric acid were dried for FTIR and XRD analysis. Enamel disks etched with tartaric acid for 60 s were analyzed by attenuated total reflectance (ATR). Enamel disks etched with 15% tartaric acid for 15, 30, 60, 120 s were analyzed by SEM. FTIR spectra showed carboxylate in the solid and in subtraction spectra. ATR spectra revealed carboxylate on the enamel surfaces. XRD data indicated the formation of calcium tartrate and calcium hydrogen phosphate after the reaction of tartaric acid with hydroxyapatite. SEM observations revealed typical decalcification of the periphery of the enamel rods due tartaric acid etching. It is concluded that tartaric acid can decalcify and chemisorb onto HA simultaneously, hence, tartaric acid could be used as etchant and ingredient of self-etching primers in adhesive dentistry.

Acid Etching, Dental↗

PubMed2005

Comparison of CHOP versus CIOP in good prognosis younger patients with histologically aggressive non-Hodgkin lymphoma.

CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone) has been the standard chemotherapy regimen used for diffuse large cell lymphomas for over 30 years. Idarubicin is a 4-demethoxy-anthracycline analogue of daunorubicin that has proven activity in non-Hodgkin lymphoma, and has been reported to cause less cardiotoxicity. We therefore initiated a randomised trial of standard dose CHOP versus CIOP (cyclophosphamide, idarubicin, vincristine and prednisolone), in which doxorubicin 50 mg/m2 was substituted by idarubicin 10 mg/m2, a dose thought to have equivalent anti-lymphoma activity. This trial was closed prematurely after 211 patients had completed therapy when a lower complete remission (CR) rate was noted in the CIOP arm. The formal results with long-term follow up are now reported. Overall response rate was 84% in the CHOP arm and 78% in the CIOP arm, CR rates were 70% and 52% respectively in all patients (P=0.013) and 73% and 52% respectively for the eligible patients (P=0.0084). At a median of 8 years follow-up, 4-year progression-free survival for all patients was 56% in the CHOP arm and 40% in the CIOP arm (P=0.0096). Overall survival for all patients was 65% in the CHOP arm and 56% in the CIOP arm (P=0.14). Results for eligible patients were comparable. CIOP containing idarubicin at a dose of 10 mg/m2 is clearly inferior to standard CHOP.

Adult↗

PubMed2004

Detection of the putative cis-region involved in the induction by a Pyricularia oryzae elicitor of the promoter of a gene encoding phenylalanine ammonia-lyase in rice.

A rice PAL (phenylalanine ammonia-lyase) gene sequence ( rPAL-P5), which is highly similar to and likely the same as a previously described rice ZB8PAL gene, including the 5'-upstream and exon I coding regions of PAL, was isolated using PCR amplification. The expression of several PALs, including rPAL-P5, was strongly induced following inoculation with Pyricularia oryzae or treatment with a P. oryzae elicitor. To identify the promoter region induced by the P. oryzae elicitor, we constructed and subsequently transformed rPAL-P5 promoter deletion series into rice calli using particle bombardment. Results from both elicitor-inducible reporter gene and gel mobility shift assays demonstrated that the sequence -349 to -256 of the rPAL-P5 promoter includes a cis-element involved in the induction of P. oryzae.

Base Sequence↗

PubMed2004

Telomerase activity in B and T lymphocytes of patients with systemic lupus erythematosus.

OBJECTIVE: To evaluate telomerase activity as a marker of lymphocyte proliferation in systemic lupus erythematosus (SLE). METHODS: CD19+, CD4+, and CD8+ lymphocytes were isolated from the peripheral blood of nine patients with SLE and nine healthy controls by means of magnetic bead-coupled antibodies and tested for telomerase activity with the TRAP assay. RESULTS: Telomerase activity was significantly increased in CD19+ B cells from patients with SLE. CD4+ and CD8+ T cells from lupus patients displayed increased mean telomerase activity, although the difference from normal controls did not reach statistical significance. CONCLUSIONS: Increased telomerase activity in the B and the T cell lineage might indicate activation and proliferation of these lymphocytes.

B-Lymphocyte Subsets↗

PubMed2004

BTS randomised feasibility study of active symptom control with or without chemotherapy in malignant pleural mesothelioma: ISRCTN 54469112.

BACKGROUND: The incidence of mesothelioma is rising rapidly in the UK. There is no generally accepted standard treatment. The BTS recommends active symptom control (ASC). It is not known whether chemotherapy in addition prolongs survival or provides worthwhile palliation with acceptable toxicity. Palliation as recorded by patients has been fully reported for only two regimens: mitomycin, vinblastine, and cisplatin (MVP), and vinorelbine (N). The BTS and collaborators planned to conduct a phase III randomised trial comparing ASC only, ASC+MVP, and ASC+N in 840 patients with survival as the primary outcome measure. The aim of the present study was to assess the acceptability of the trial design to patients and the suitability of two standard quality of life (QL) questionnaires for mesothelioma. METHODS: Collaborating centres registered all new patients with mesothelioma. Those eligible and giving informed consent completed EORTC QLQ-C30+LC13 and FACT-L QL questionnaires and were randomised between all three or any two of (1) ASC only, (2) ASC+4 cycles of MVP, and (3) ASC+12 weekly doses of N. RESULTS: During 1 year, 242 patients were registered of whom 109 (45%) were randomised (55% of the 197 eligible patients). Fifty two patients from 20 centres were randomised to an option including ASC only. This translates into a rate of 312 per year from 60 centres interested in collaborating in the phase III trial. The EORTC QL questionnaire was superior to FACT-L in terms of completeness of data and patient preference. Clinically relevant palliation was achieved with ASC. CONCLUSION: The planned phase III trial is feasible.

Adult↗

PubMed2003

Telomerase activity in B-cell non-Hodgkin lymphomas is regulated by hTERT transcription and correlated with telomere-binding protein expression but uncoupled from proliferation.

Telomere maintenance is a prerequisite for immortalisation, and in most malignant cells is carried out by telomerase, an enzyme that synthesis new telomeric repeats on the chromosome ends. In normal or reactive tissues with a high regenerative capacity, telomerase is regulated according to the telomere loss that occurs during proliferation. To evaluate the interaction of proliferation and telomerase activity in malignant lymphomas, we quantified telomerase expression in different non-Hodgkin lymphomas in comparison to normal or reactive lymph nodes. Surprisingly, the activity levels were the same in most of the lymphomas analysed as compared to reactive lymph nodes. Significantly higher activity was detected only in Burkitt's lymphoma. Telomerase activity correlated well with hTERT and c-myc expression, but was independent of proliferation. To evaluate interactions of telomere-binding protein expression on telomerase expression in non-Hodgkin lymphoma, the mRNA levels of TRF1, TRF2, tankyrase and hPif1 were assessed by real-time RT-PCR. We demonstrate here that the magnitude of telomerase upregulation does not necessarily reflect the requirement of telomere compensation caused by proliferation. Telomerase regulation in non-Hodgkin lymphomas is therefore uncoupled from proliferative stimuli found in reactive lymphoid tissue. We suggest that the upregulation of specific telomere-binding proteins like TRF2 may contribute to telomere maintenance in malignant lymphoma.

Biomarkers, Tumor↗

PubMed2003

Paclitaxel plus platinum-based chemotherapy versus conventional platinum-based chemotherapy in women with relapsed ovarian cancer: the ICON4/AGO-OVAR-2.2 trial.

BACKGROUND: Despite improvements in the treatment of ovarian cancer, most patients develop recurrent disease within 3 years of diagnosis. There is no agreed second-line treatment at relapse. We assessed paclitaxel plus platinum chemotherapy as such treatment. METHODS: In parallel international, multicentre, randomised trials, between January, 1996, and March, 2002, 802 patients with platinum-sensitive ovarian cancer relapsing after 6 months of being treatment-free were enrolled from 119 hospitals in five countries. Patients were randomly assigned paclitaxel plus platinum chemotherapy or conventional platinum-based chemotherapy. Analysis was by intention to treat, except for toxic effects. FINDINGS: With a median follow-up of 42 months, 530 patients have died. Survival curves showed a difference in favour of paclitaxel plus platinum (hazard ratio 0.82 [95% CI 0.69-0.97], p=0.02), corresponding to an absolute difference in 2-year survival of 7% between the paclitaxel and conventional treatment groups (57 vs 50% [95% CI for difference 1-12]), and median survival of 5 months (29 vs 24 months [1-11). 717 patients developed progressive disease or died. The progression-free survival curves show a difference in favour of paclitaxel plus platinum (hazard ratio 0.76 [0.66-0.89], p=0.0004), corresponding to an absolute difference in 1-year progression-free survival of 10% (50 vs 40% [4-15]) and in median progression-free survival of 3 months (13 vs 10 months [1-5]). INTERPRETATION: Paclitaxel plus platinum chemotherapy seems to improve survival and progression-free survival among patients with relapsed platinum-sensitive ovarian cancer compared with conventional platinum-based chemotherapy.

Aged↗

PubMed2003

DNA damage transiently increases TRF2 mRNA expression and telomerase activity.

Telomerase activity transiently increases when HL60 cells are treated with the topoisomerase II inhibitor etoposide. A quantitative assessment revealed that telomerase is activated by etoposide treatment in a number of cell lines and that the increase is reversible after withdrawal of etoposide from the cell culture. Telomerase activation correlated with the occurrence of DNA damage but not with cell cycle arrest. We did not detect any transcriptional upregulation of hTERT mRNA, suggesting a post-transcriptional mechanism of telomerase activation. Furthermore, the mRNA expression of the telomere binding protein TRF2 was upregulated early and reversibly after etoposide treatment. TRF1 mRNA expression levels were unchanged after DNA damage, but increased when the cells accumulated in the G2/M phase. The data show that the telosome reacts after DNA damage by upregulating telomerase activity and TRF2 expression in malignant cells. It has previously been shown that overexpression of TRF2 can repress senescence signals arising from critically shortened telomeres. We show here that TRF2 is upregulated by undirected DNA damage that also affects the telomeric DNA. These data suggest that upregulation of telomerase activity and TRF2 expression might act as antiapoptotic mechanisms in the DNA-damage response of malignant cells.

Cell Cycle↗

PubMed2002

First-line treatment for advanced ovarian cancer: paclitaxel, platinum and the evidence.

Four large randomised trials of paclitaxel in combination with platinum against a platinum-based control treatment have now been published in full, representing around 88% (3588 out of 4057) of patients randomised into the eight known trials of this question. There is substantial heterogeneity in the results of these four trials. Four main explanations for this heterogeneity have been proposed: differences in the extent and timing of 'crossover' to taxanes in the control groups; differences in the types of patient included; differences in the effectiveness of the research regimens used; differences in the effectiveness of the control regimens used. In this study we examine whether any of these explanations is consistent with the pattern of results seen in these trials. Each explanation suggests that a particular characteristic of each trial was responsible for the results observed. For each explanation the trials were split into groups according to that characteristic, in order to partition the total heterogeneity into that seen 'within' and 'between' groups of trials. If a particular explanation was consistent with the pattern of results, we would expect to see relatively little heterogeneity within each group of trial results viewed in this way, with most of the heterogeneity being between groups which are dissimilar with respect to the key characteristic. Heterogeneity 'within' and 'between' groups was formally compared using the F-ratio. If any explanation appeared to be consistent with the results of the trials, it was considered whether the explanation was also consistent with other evidence available about these regimens. Only one explanation appeared to be consistent with the pattern of results seen in these trials, and that was differences in effectiveness of the control arms used in these trials. This suggests that the very positive results in favour of paclitaxel/cisplatin seen in two of the trials may have been due to the use of a suboptimal control arm. There is no direct evidence about the relative effectiveness of the control arms used in these trials, but indirect evidence is consistent with the conclusion that the cyclophosphamide/cisplatin regimen used in two of the trials may be less effective than the control regimens used in the other trials. Specific concerns about the choice of a cyclophosphamide/cisplatin control arm in the first of these trials to report were raised before the results of the other trials were known, i.e. before any heterogeneity had been observed. Further investigation of this question would be useful. In the meantime, given all of the randomised evidence on the efficacy and toxicity associated with the regimens used in these trials, we conclude that single agent carboplatin is a safe and effective first-line treatment for women with advanced ovarian cancer.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2002

Advances in micro-calcification clusters detection in mammography.

A new mixed feature multistage false positive (FP) reduction method for micro-calcification clusters (MCCs) detection has been developed for improving the FP reduction performance. Eleven features were extracted from both spatial and morphology domains in order to describe MCCs from different perspectives. These features are grouped into three categories: gray-level description, shape description and clusters description. Two feature sets that focus on describing MCCs on every single calcification and on clustered calcifications, respectively, were combined with a back-propagation (BP) neural network with Kalman filter to obtain the best performance of FP reduction. First, nine of the eleven gray-level description and shape description features were employed with BP neural network to eliminate all the obvious FP calcifications in the image. Second, the remaining MCCs were classified into several clusters by a widely used criterion in clinical practice and then two cluster description features were added to the first feature set to eliminate the FP clusters from the remaining MCCs. The performance results of this approach were obtained using an image database of 67 real-patients mammogram images in H. Lee Moffitt Cancer Center imaging program. The proposed method successfully reduced the FP to 3.15/image, while the detection sensitivity or true positive rate improved to 97%.

Algorithms↗

PubMed2002

[Cloning and analysis of a novel gene encoding N-terminal acetyltransferase subunit].

N-terminal acetylation is the most common modification in eukaryotic proteins, affecting stability and activity of proteins. NatA is one of the N-terminal acetytransferases in yeast. It is composed of two subunits, NAT1 and ARD1. Defect in one of them leads to loss of activity of NatA. Null mutant of NAT1 in yeast exhibits a variety of phenotypes, including depression of a silent mating type locus (HML), failing to enter G(0) in poor nutrient situations and chromosomes instability. Based on homology of NAT1 between yeast and other organisms, the full-length CDS (coding sequence) of HNAT1 was cloned and sequenced. Result of in situ hybridization in testis of rat showed that expression of NAT1 was high and its expression was different in different phases of spermatogenesis. The gene may play an important role in spermatogenesis.

Acetyltransferases↗