Tomoko Chiba

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Eukaryotic transcription activation domains (ADs) are not well defined on the proteome scale. We systematicallly tested approximately 6000 yeast proteins for transcriptional activity using a yeast one-hybrid system and identified 451 transcriptional activators. We then determined their transcription activation strength using fusions to the Gal4 DNA-binding(More)
Transcriptionally active and inactive domains are frequently found adjacent to one another in the eukaryotic nucleus. To better understand the underlying mechanisms by which domains maintain opposing transcription patterns, we performed a systematic genomewide screen for proteins that may block the spread of silencing in yeast. This analysis identified(More)
It is well documented that human immunodeficiency virus type 1 (HIV-1) Gag cleavage site mutations (CSMs) emerge in conjunction with various HIV-1 mutations for protease inhibitor (PI) resistance and improve viral replication capacity, which is reduced by acquisition of the resistance. However, CSMs are not the only mutations that emerge in Gag during(More)
Comprehensive analysis of protein-protein interactions is a challenging endeavor of functional proteomics and has been best explored in the budding yeast. The yeast protein interactome analysis was achieved first by using the yeast two-hybrid system in a proteome-wide scale and next by large-scale mass spectrometric analysis of affinity-purified protein(More)
Glucokinase, an enzyme that catalyzes the phosphorylation of glucose, constitutes the key regulatory step in glucose metabolism in pancreatic islets and liver. We found that 3-O-methyl-N-acetyl-D-glucosamine (3-O-methyl-GlcNAc) potently inhibits glucose phosphorylation by N-acetylglucosamine kinase whereas glucokinase is not at all affected by this(More)
We established a strategy to constitutively activate Zn(2)Cys(6)-type protein by fusing its DNA-binding domain with the VP16 trans-activation domain. To explore gene network regulating yeast multidrug resistance, the strategy was applied to Pdr1, Pdr3 and Yrr1, known to regulate multidrug resistance, as well as three uncharacterized Yrr1-related(More)
We examined the effects of a newly synthesized gastrin receptor antagonist, AG-041R, on the growth of enterochromaffin-like (ECL) carcinoid tumors in Mastomys natalensis both in vitro and in vivo. AG-041R was as potent as the well known gastrin antagonist L365,260 in inhibiting not only the gastrin-induced release of histamine from but also histidine(More)
A rapid zidovudine (ZDV) resistance genotypic assay was developed based on the mutagenically separated PCR (MS-PCR) technique to detect two ZDV-resistant mutations, M41L and K70R in CRF01_AE (subtype E). Endpoint dilution analysis revealed that the newly constructed MS-PCR assay could successfully detect three to nine copies of human immunodeficiency virus(More)
We constructed a novel tool for genotypic analysis of human immunodeficiency virus type 1 (HIV-1) drug resistance by using an enzyme-linked minisequence assay (ELMA). ELMA is a combination of hybridization and a 1-base extension reaction, and we designed the assay to detect five mutations conferring nucleoside analogue resistance (M41L, D67N, K70R, T215Y,(More)
Here we report that sparsomycin, a streptococcal metabolite, enhances the replication of HIV-1 in multiple human T cell lines at a concentration of 400 nM. In addition to wild-type HIV-1, sparsomycin also accelerated the replication of low-fitness, drug-resistant mutants carrying either D30N or L90M within HIV-1 protease, which are frequently found(More)