Xenopus laevis 난세포에서 Sphingosine-1-phosphate와 Lysophosphatidic acid에 의한 신호 전달 기작 연구

Maste

애기장대에서 소포체 스트레스 반응의 특성 규명

학위논문(박사) - 한국과학기술원 : 생물과학과, 2002.8, [ ix, 102 p. ]The accumulation of unfolded proteins in the endoplasmic reticulum (ER) elicits an ER-to-nucleus signaling pathway known as the unfolded protein response (UPR) in eukaryotes. In yeast, Ire1p, a kinase/endoribonuclease in the ER membrane, plays as a key proximal sensor molecule in the UPR signaling. To elucidate the molecular mechanism involved in the unfolded protein response in plant, I isolated two cDNA homologs of IRE1 gene from Arabidopsis (AtIRE1a, AtIRE1b). The two IRE1 homologs were predicted to encode type I transmembrane proteins, which contain lumenal domain at N-terminal halves and a kinase/endoribonuclease domains at their C-terminal halves. The expressions of the two genes were detected in various organ tissues of the Arabidopsis plant in Northern blot analysis. Using GST-fused recombinant protein, it was demonstrated that the C-terminal half of the AtIre1a protein has in vitro autophosphorylation activity. However, I could not detect endoribonuclease activity of the AtIre1a protein when I used yeast HAC1 RNA as a substrate in vivo in transient expression using Arabidopsis protoplast. As an attempt to find the UPR-regulated genes in Arabidopsis by overall genome scale, I have performed the gene expression analysis using oligonucleotide genome array, which contains probes against more than 8,200 genes and 100 EST clusters for Arabidopsis thaliana. From the Northern analysis, optimized condition for the tunicamycin treatment to Arabidopsis seedlings were established, that is 5㎍/ml$ tunicamycin treatment for 4 hr. Through gene expression profiling experiments using 4 genechips for mock-treated control and 4 genechips for tunicamycin(Tm)-treated respectively, 32 genes, which occupies 0.4 % of the tested total genes, were revealed as tunicamycin-upregulated. Among them, ER chaperones such as BiPs, protein disulfide isomerases, calnexins, some of heat-shock proteins working in the ER lumen, calreticulins, and the genes involved in protein transport suc...한국과학기술원 : 생물과학과

Complete mitochondrial genome of Pacific abalone (Haliotis discus hannai) from Korea

We have sequenced and characterized the complete mitochondrial DNA of an economically and ecologically important Pacific abalone, Haliotis discus hannai (Haliotidae, Gastropoda). The mitogenome of the Pacific abalone is 16,886 nt total length with a 39.6% GþC composition. Thirty-seven genes were identified including 13 protein-coding, 2 rRNA and 22 tRNA genes. We compared the mitogenome of the Pacific abalone to a putative relative species, H. rubra.th with a 39.6% GþC composition. Thirty-seven genes were identified including 13 protein-coding, 2 rRNA and 22 tRNA genes. We compared the mitogenome of the Pacific abalone to a putative relative species, H. rubra.1