배아줄기세포 연구에서 좀더 조심스럽게 고려해야 할 사안들

한징택 서강대학교 생명문화연구소 2007 생명연구 Vol.8 No.-

초파리 세포에서의 EF - 1α 의 동정 및 특성에 관한 연구

한징택 한국유전학회 1996 Genes & Genomics Vol.18 No.1

EF-l α protein is identified and partially purified in Drosophila. EF-l α appeares as double bands of 49 and 51 KD on SDS-polyacrylamide gel. Both are basic proteins and bind to GTP as EF-1 α protein in other organisms. Polyclonal antibodies were prepared against both 49 kD and 51 kD protein in the rabbit. The antibodies crossreact with both Drosophila and yeast EF-1 α In Drosophila Kc cells it is shown that EF-1 α exists as heterogeneous forms of 49-400 KD in the physiological condition.

과학기술에 있어서 생명과 인간 존엄성

한징택 서강대학교 생명문화연구원 2003 생명연구 Vol.5 No.-

초파리 Kc 세포에서의 EF-1α 유전자의 발현

이용준,한징택,김광종,신계호,황서하 한국유전학회 1998 Genes & Genomics Vol.20 No.1

The change of protein synthesis by heat shock has been studied showing some alterations in translation elongation step in addition to initiation step. In heat shocked Drosophila cells the elongation rate on control messages is slower than that of on heat shock messages. EF-1α has been considered as a candidate for the altered factor by heat-shock, which might discriminate heat shock messages vs control messages in Drosophila cells. To find the regulatory role of EF-1α on protein synthesis in Drosophila Kc cells, disposition of EF-1α from heat shocked and control Kc cells on Non-equilibrium pH gradient two-dimensional gel (NEPHGE) was examined. No disposition change of EF-1α from heat shocked cells was observed on NEPHGE compared to that of control cells implying that EF-1α itself was not post-translationaly modified by heat shock. For the study of EF-1α expression in Kc cells under stress condition, EF-1α gene, F1 has been cloned and the expression of EF-1α gene was investigated in Kc cells showing that Kc cells have two EF-1α genes and only one gene is expressed under normal condition.

비정상적 정자형성 환자의 정소에서 Heat Shock Protein A2 (hspA2) mRNA 발현의 감소

손원영,황서하,한징택,이재호,김석중,김영찬,Son, W.Y.,Hwang, S.H.,Han, C.T.,Lee, J.H.,Kim, S.J.,Kim, Y.C. 대한생식의학회 1999 Clinical and Experimental Reproductive Medicine Vol.26 No.1

Objective: Heat shock protein 70-2 (Hsp70-2) gene knockout mice are found to have premeiotic arrest at the primary spermatocyte stage with a complete absence of spermatids and spermatozoa. This observation led to the hypothesis that hspA2 may be disrupted in human testes with abnormal spermatogenesis. To test this hypothesis, we studied the mRNA expression of hspA2 in infertile men with azoospermia. Design: The mRNA expression were analyzed by competitive RT-PCR among testes with normal spermatogenesis, pachytene spermatocyte arrest, and sertoli-cell only syndrome. Materials and methods: Testicular biopsy was performed in men with azoospermia (n=15). Specimens were subdivided into three groups: (group 1) normal spermatogenesis (n=5), (group 2) spermatocyte arrest (n=5), (group 3) Sertoli-cell only syndrome (n=5). Total RNA was extracted by Trizol reagent. Total extracted RNA was reverse transcribed into cDNA and amplified by PCR using specific primers for hspA2 target cDNAs. A competitive cDNA fragment was constructed by deleting a defined fragment from the target cDNA sequence, and then coamplified with the target cDNA for competitive PCR. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was used as an internal control. Results: On Competitive RT-PCR analyses for hspA2 mRNA, significant amount of hspA2 expression was observed in group 1, whereas a constitutively low level of hspA2 was expressed in groups 2 and 3. Conclusion(s): The study demonstrates that the hspA2 gene expression is down-regulated in human testes with abnormal spermatogenesis, which in turn suggests that hspA2 gene may play a specific role during meiosis in human testes.

Allelic variation in Brassica oleracea CIRCADIAN CLOCK ASSOCIATED 1 (BoCCA1) is associated with freezing tolerance

송하영,이한길,한징택,박종인,허윤강 한국원예학회 2018 Horticulture, Environment, and Biotechnology Vol.59 No.3

Freezing tolerance is an important horticultural trait in cabbage (Brassica oleracea). Molecular markers for freezing tolerance are needed for marker-assisted breeding of freezing-tolerant cabbage plants. To develop gene-based molecular markers for freezing-tolerance in cabbage, we focused on CIRCADIAN CLOCK ASSOCIATED 1 (CCA1), a core circadian clock component that affects metabolic pathways and confers cold tolerance by upregulating C-repeat binding factor (CBF) pathway genes. We cloned and analyzed CCA1 genes (BoCCA1s) from seven inbred lines and one cultivar of B. oleracea ssp. capitata. Two types of BoCCA1 alleles were detected: BN106-type (freezing-tolerant; BoCCA1-1) and BN107-type (freezing-susceptible; BoCCA1-2). Numerous insertions/deletions (InDels), simple sequence repeats, and single nucleotide polymorphisms (SNPs) were found in the exons and introns of BoCCA1s from the ATG start codon at the second exon to the TGA stop codon at the eighth exon. Using InDels and SNPs, we designed PCR primer pairs to distinguish the freezing-tolerant lines, and validated these markers using 102 cabbage lines and cultivars. The inbred lines possessed either the BN106-type or BN107-type allele, but most cultivars had both alleles. Freezing-tolerant cabbage plants had BN106-type InDels and/or BN106-type SNPs regardless of the presence of BN107-type InDels and SNPs, and BN106-type SNPs were more widely detected in the freezing-tolerant cabbage plants than BN106-type InDels. The expression patterns of BoCCA1-1 and BoCCA1-2 were similar under normal versus temperature-stressed conditions (low and high temperatures), suggesting a functional difference at the post-transcriptional level. Cabbage breeders should use several markers derived from different genes and independently established inbred lines from different seed companies.

인간 조직에서 Heat Shock Protein A2 (HspA2) 단백질의 발현

손원영,황서하,한징택,이재호,최윤정,김석중,김영찬,Son, W.Y.,Hwang, S.H.,Han, C.T.,Lee, J.H.,Choi, Y.J.,Kim, S.,Kim, Y.C. 대한생식의학회 1999 Clinical and Experimental Reproductive Medicine Vol.26 No.2

In mouse, the heat shock protein 70-2 (hsp70-2) is found to have special function in spermatogenesis. Based on the observation, the hypothesis that human hspA2 (human gene; 98.2% amino acid homology with hsp70-2) might have important function in spermatogenesis in human testes was proposed. To test the hypothesis, we examined the expression of hspA2 in human tissues. Expression vector pDMC4 for expression of the human hspA2 protein using pTricHisB (invitrogen, USA) was constructed and the expressed hspA2 protein was cross-reacted with antiserum 2A raised against mouse hsp70-2 protein. Based on the cross-reactivity, we determined the expression level of hspA2 protein in human tissues by western blot analysis using the antiserum 2A. We demonstrated that antiserum 2A antibodies detected human hspA2 protein with specificity which was produced in the E.coli expression system. On Western blot analyses, significant hspA2 expression was observed in testes with normal spermatogenesis, whereas a low level of hspA2 was expressed in testis with Sertoli-cell only syndrome. Also, a small amount of hspA2 was detected in breast, stomach, prostate, colon, liver, ovary, and epididymis. These results demonstrate that the hspA2 protein is highly expressed in male specific germ cells, which in turn suggests that hspA2 protein might playa specific role during meiosis in human testes as suggested in the murine model. However, further studies should be attempted to determine the function of hspA2 protein in human spermatogenesis.

Genome-wide expression profiles of contrasting inbred lines of Chinese cabbage, Chiifu and Kenshin, under temperature stress

이정여,임용표,한징택,노일섭,허윤강 한국유전학회 2013 Genes & Genomics Vol.35 No.3

Abiotic stresses such as extreme temperatures frequently limit plant growth and productivity of major crop species. To identify temperature-stress responsive genes in Brassica rapa ssp. pekinensis, we conducted a comparative transcriptome analysis of two contrasting genotypes, the inbred lines Chiifu and Kenshin, under and heat-shock conditions. Of 23,929 unigenes deposited on a Br24Kmicroarray,17,603 genes were significantly expressed. Chiifu expression profiles were more prevalent under , and those of Kenshin were more prevalent under heat-shock. Previously characterized genes, with little exception, show similar changes to temperature stress. We found that a relatively large number of genes were expressed in response to temperature stress and genotype,amounting to 24 and 126 genes fromand heat-shock conditions, respectively. These genes could be used in molecular marker development for either high or low temperature-resistant Brassica spp. Only ten genes, including TCH4 and CBL1, were up-regulated in both genotypes under all stress treatments, implying possible candidates for broad spectrum, stress-resistant crop production.

Overexpression of BrMORN, a Novel ‘Membrane Occupation and Recognition Nexus’ Motif Protein Gene from Chinese Cabbage, Promotes Vegetative Growth and Seed Production in Arabidopsis

Jeongyeo Lee,한징택,Yoonkang Hur 한국분자세포생물학회 2010 Molecules and cells Vol.29 No.2

Proteins that contain membrane occupation and recognition nexus (MORN) motifs regulate various aspects of cellular metabolism by localizing proteins in different cellular organ-elles. The full-length Brassica rapa MORN motif protein (BrMORN) cDNA consists of 1,510 bp encoding 502 de-duced amino acids with a predicted molecular mass of 55.8 kDa and an isoelectric point of 9.72. BrMORN is a novel pro-tein composed of two N-terminal transmembrane helices and seven C-terminal MORN motifs and it appears to be localized on the plastid envelope. BrMORN expression was relatively high in actively-growing tissues, but low in mature tissues and under some abiotic stresses. Arabidopsis thaliana plants overexpressing BrMORN showed an en-hanced rate of growth, hypocotyl elongation, and increases in the size of vegetative organs and seed productivity under normal growth conditions. In addition, cell size in Arabidop-sis plants overexpressing BrMORN was 24% larger than that of wild-type plants, implying that the increase in the size of vegetative organs is due to cell enlargement. The increased size of the vegetative organs also led to increased seed production. Our data suggest that the MORN motif of BrMORN may act at the plastid envelope and facilitate plant growth via cell enlargement.

Conservation of cis-Regulatory Element Controlling TimelyTranslation in the 3'-UTR of Selected Mammalian MaternalTranscripts

이현주,임윤기,장상호,민관식,한징택,황수연 한국유전체학회 2007 Genomics & informatics Vol.5 No.4

The earliest stages of mammalian embryogenesis are governed by the activity of maternally inherited transcripts and proteins. Cytoplasmic polyadenylation of selected maternal mRNA has been reported to be a major control mechanism of delayed translation during preimplantation embryogenesis in mice. The presence of cis-elements required for cytoplasmic polyadenylation (e.g., CPE) can serve as a useful tag in the screening of maternal genes partaking in key functions in the transcriptionally dormant egg and early embryo. However, due to its relative simplicity, UA-rich sequences satisfying the canonical rule of known CPE consensus sequences are often found in the 3’-UTR of maternal transcripts that do not actually undergo cytoplasmic polyadenylation. In this study, we developed a method to confirm the validity of candidate CPE sequences in a given gene by a multiplex comparison of 3’-UTR sequences between mammalian homologs. We found that genes undergoing cytoplasmic polyadenylation tend to create a conserved block around the CPE, while CPE-like sequences in the 3’-UTR of genes lacking cytoplasmic polyadenylation do not exhibit such conservation between species. Through this cross-species comparison, we also identified an alternative CPE in the 3’-UTR of tissue-type plasminogen activator (tPA), which is more likely to serve as a functional element. We suggest that verification of CPEs based on sequence conservation can provide a convenient tool for mass screening of factors governing the earliest processes of mammalian embryogenesis