Hiroyuki Tachikawa

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TRIM11 is a member of the tripartite-motif-containing protein family and is known to destabilize humanin, an inhibitor of Alzheimer-like neuronal insults. In this study, we demonstrate that TRIM11 interacts with activator-recruited cofactor 105-kDa component (ARC105) that mediates chromatin-directed transcription activation and is a key regulatory factor(More)
Protein N-glycosylation begins with the assembly of a lipid-linked oligosaccharide (LLO) on the endoplasmic reticulum (ER) membrane. The first two steps of LLO biosynthesis are catalyzed by a functional multienzyme complex comprised of the Alg7 GlcNAc phosphotransferase and the heterodimeric Alg13/Alg14 UDP-GlcNAc transferase on the cytosolic face of the(More)
Glycosylation site binding protein (GSBP) has been shown to be identical to protein disulfide isomerase (PDI; EC in a variety of multicellular organisms. We have utilized immunological and biochemical techniques to determine if GSBP and PDI are identical in yeast. Antiserum prepared against yeast GSBP identified in microsomes by its ability to be(More)
N-linked glycosylation requires the synthesis of an evolutionarily conserved lipid-linked oligosaccharide (LLO) precursor that is essential for glycoprotein folding and stability. Despite intense research, several of the enzymes required for LLO synthesis have not yet been identified. Here we show that two poorly characterized yeast proteins known to be(More)
Sporulation of Saccharomyces cerevisiae is a developmental process in which a single cell is converted into four haploid spores. GIP1, encoding a developmentally regulated protein phosphatase 1 interacting protein, is required for spore formation. Here we show that GIP1 and the protein phosphatase 1 encoded by GLC7 play essential roles in spore development.(More)
During yeast sporulation, a forespore membrane (FSM) initiates at each spindle-pole body and extends to form the spore envelope. We used Schizosaccharomyces pombe to investigate the role of septins during this process. During the prior conjugation of haploid cells, the four vegetatively expressed septins (Spn1, Spn2, Spn3, and Spn4) coassemble at the fusion(More)
Ascospore formation in yeast is accomplished through a cell division in which daughter nuclei are engulfed by newly formed plasma membranes, termed prospore membranes. Closure of the prospore membrane must be coordinated with the end of meiosis II to ensure proper cell division. AMA1 encodes a meiosis-specific activator of the anaphase promoting complex(More)
In Saccharomyces cerevisiae, nutrient limitation stimulates diploid cells to undergo DNA replication and meiosis, followed by the formation of four haploid spores. Septins are a family of proteins that assemble a ring structure at the mother-daughter neck during vegetative growth, where they control cytokinesis. In sporulating cells, the septin ring(More)
MPD1, a yeast gene the overexpression of which suppresses the inviability caused by the loss of protein disulfide isomerase (PDI) was isolated and characterized. The MPD1 gene product retained a single disulfide isomerase active site sequence (APWCGHCK), an N-terminal putative signal sequence, and a C-terminal endoplasmic reticulum (ER) retention signal,(More)
Acephate (AT) is an organophosphate (OP) insecticide. Due to their reputation for low environmental persistence, OP pesticides are often used indiscriminately resulting in detrimental exposure to humans and other nontarget species. Although the toxicity of OP compounds is primarily through blockade of neural transmission via inhibition of(More)