• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.3
• /
• pp.273-276
• /
• 2006

RNA interference (RNAi), a process of sequence-specific gene suppression, has been known as a natural gene regulatory mechanism in a wide range of lower organisms. Recently, we have reported that a transfection of human U6 promoter (hU6) driven hairpin small-interference RNA (siRNA) plasmid specifically knocks down the target gene by post-transcriptional gene silencing in mammalian cells. Here we report that transfection of polymerase chain reaction (PCR) products, containing human U6 promoter with hairpin siRNA, knocks down the target gene expression in human teratocarcinoma NT-2/D1 cells. Moreover, we showed 3' end termination sequence, 5 Ts, is not critical elements for knocking down in PCR-based siRNA system. Therefore, the PCR-based siRNA system is a promising tool not only for the screening but also to temporally regulate gene expression in the human progenitor cells.

• Journal of Life Science
• /
• v.10 no.2
• /
• pp.12-13
• /
• 2000

A human-specific retroposon SINE-R.C2 has been derived from a human endogenous retrovirus HER V-K 10. It is absent in the genome of nonhuman primates and present within the third intron of the human C2 gene that is located in the class III region of the major histocompatibility complex. In the present study, we determined the regional location of the human C2 gene. The analysis of the Genebridge 4 radiation hybrid mapping panel using PCR amplification located the C2 gene between D6S1422 (10.1 cR) and CHLC.GATA4A03 (21.3) with a lod score of>3.0. This allowed us to localize C2 gene on the human chromosome 6 band p21.31.

• Animal cells and systems
• /
• v.7 no.1
• /
• pp.63-68
• /
• 2003

Until recently, interest in human complement receptor type I (CR1) has focused on immune complex processing, which contributed to our understanding of regulatory mechanism of complement activation. However, the promoter structure and transcriptional regulation of human CR1 gene has not been clear. To study the unique regulation of human CR1 gene expression, we assessed promoter activity of the $5^1$-flanking region of human CR1 gene using transient transfection and gel mobility shift assays. In this study we demonstrated that NF-Y binds to the inverted CCAAT element and that the functional interaction with protein(s) which bind to the GC-rich motif may be necessary for optimal transcription of human CR1 gene. We also show that sequence elements which located at-95/58 and +45/+50 are important for optimal transcription of CR1 gene.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.1
• /
• pp.9-14
• /
• 1999

Factors affecting gene gun-mediated expression of the human erythropoietin gene were investigated in primary cultured oviduct cells from laying hens. The human erythropoietin gene was transfected by a gene gun method at $1.25{\mu}g$ per dish, and cultured in a synthetic serum-free medium for 72 hrs. The concentration of human erythropoietin mRNA was determined by RNA : RNA solution hybridization. In experiment 1, the effect of changing the shooting pressure of DNA-coated microparticles with nitrogen gas was tested at 20 and $60kgf/cm^2$. The results showed that the erythropoietin mRNA concentration was significantly higher at 60 than $20kgf/cm^2$. In experiment 2, the effects of supplementing the medium with fetal calf serum at 10%, and raising the shooting pressure from 60 to $80kgf/cm^2$ on the cell number and erythropoietin gene expression were examined. Although supplementation with fetal calf serum significantly increased the cell numbes compared with no supplemented controls (p < 0.05), erythropoietin mRNA concentration per $10^3$ cells was not affected. Raising the shooting pressure from 60 to $80kgf/cm^2$ did not affect either of the parameters, In experiment 3, the effect of supplementing ascorbate 2-phosphate at 0.5 mM was tested. The results indicated that the ascorbate supplementation significantly increased the cell number (p < 0.05), and tended to increase erythropoietin mRNA concentration (p < 0.1). Thus, for human erythropoietin gene expression by using the gene gun method, shooting pressure with nitrogen gas should be sufficient at $60kgf/cm^2$ and supplementation with ascorbate phosphate would be useful to enhance not only the cell proliferation but also erythropoietin gene expression.

• IMMUNE NETWORK
• /
• v.2 no.2
• /
• pp.79-85
• /
• 2002

Background: In contrast to evidences of Ig H chain receptor editing in transformed cell lines and transgenic mouse models, there has been no direct evidence that this phenomenon occurs in human developing B cells. Methods: $V_HDJ_H$ rearrangements were obtained from genomic DNA of individual $IgM^-$ B cells from liver and $IgM^+B$ cells from bone marrow of 18 wk of gestation human fetus by PCR amplification and direct sequencing. Results: We found three examples of H chain receptor editing from $IgM^+$ and $IgM^-human$ fetal B cells. Two types of $V_H$ replacements were identified. The first involved $V_H$ hybrid formation, in which part of a $V_H$ gene from the initial VDJ rearrangement is replaced by part of an upstream $V_H$ gene at the site of cryptic RSS. The second involved a gene conversion like replacement of CDR2, in which another $V_H$ gene donated a portion of its CDR2 sequence to the initial VDJ rearrangement. Conclusion: These data provide evidence of receptor editing at the H chain loci in developing human B cells, and also the first evidence of a gene conversion event in human Ig genes.

• BMB Reports
• /
• v.40 no.2
• /
• pp.270-276
• /
• 2007

We have cloned a novel mouse zinc finger protein gene Znf313 by rapid amplification of cDNA ends (RACE) according to the homologue of human ZNF313 gene. The cDNA is 2,163 base pairs (bp) in length and encodes a 229 amino acids (aa) protein with a $C_3HC_4$ ring finger domain and three $C_2H_2$ domains. 89% and 93% nucleotide (nt) and aa sequence identity is observed with its human homologue. Revealed by Northern blot and RT-PCR, full mRNA consists of 2.16 kb and widely expresses in tissues as a single transcript, most abundantly in heart, liver, kidney and testis. The expression of Znf313 in testis is detected in all development stages. Western blot analysis also reveals that Znf313 is expressed in the tissues. Immunohistochemical staining and subcellular localization demonstrate that Znf313 is expressed both in the cytoplasm and nucleus whereas predominantly localized in the nucleus. Present data suggests that Znf313 gene might play a fundamental role in gene transcription and regulation in organism and relates to spermatogenesis.

• BMB Reports
• /
• v.48 no.7
• /
• pp.373-379
• /
• 2015

Humans have acquired many distinct evolutionary traits after the human-chimpanzee divergence. These phenotypes have resulted from genetic changes that occurred in the human genome and were retained by natural selection. Comparative primate genome analyses reveal that loss-of-function mutations are common in the human genome. Some of these gene inactivation events were revealed to be associated with the emergence of advantageous phenotypes and were therefore positively selected and fixed in modern humans (the "less-ismore" hypothesis). Representative cases of human gene inactivation and their functional implications are presented in this review. Functional studies of additional inactive genes will provide insight into the molecular mechanisms underlying acquisition of various human-specific traits. [BMB Reports 2015; 48(7): 373-379]

• Journal of Pharmaceutical Investigation
• /
• v.30 no.2
• /
• pp.139-143
• /
• 2000

Gene therapy is becoming a very promising and feasible medical intervention as the understanding of human diseases extends to their molecular levels. Since the first US Food and Drug Administration (FDA)-approved human gene therapy protocol was approved in 1990, over 300 human clinical trial protocols had been approved worldwide so far. Even though some of the domestic gene therapy clinical trials also proved promising and more are awaiting, it should be emphasized that many safety aspects as well as effectiveness aspects should be considered during the development process. Moreover, there seems to be less restricted guidelines from the National Control Authority (NCA) in initiating human clinical trials. This article is intended to suggest some basis and points to consider in the development and evaluation of gene therapy products including antisense oligonucleotides pharmaceuticals.

• Journal of Microbiology
• /
• v.38 no.1
• /
• pp.24-30
• /
• 2000

US3 gene is a member of the human cytomegalovirus (HCMV) immediate early gene. Although the precise functions of the US3 gene in HCMV replication and pathogenesis are not known, it has been reported to play a role in inhibiting major histocompatibility class I antigen presentation. For further knowledge of US3 gene expression, rabbit polyclonal antiserum of the US3 gene product was used for indirect immunofluorescence assay. In permissive human foreskin fibroblast (HFF) cells, US3 gene expression was detectable as crescent or half-moon shape in the perinuclear region at immediate early times after virus infection. HFF cells infected with mutant HCMV lacking US3 open reading frames were negative for US3 immunofluorescence assay. Double immunofluorescence assay using monoclonal antibody to gamma adaptin (specific for the Golgi complex) and rabbit anti-US3 antiserum revealed that US3 gene product could be localized to the Golgi complex. At later time after HCMV infection, US3 gene products were detected as globular aggregates in the cytosol. These aggregates were positive for gamma adaptin and stained with preimmune serum, suggesting a nonspecific reaction to the Golgi complex. Northern blot analysis revealed that transcription of US3 was observed only during immediate early times after virus infection (until 6 h postinfection). Therefore US3 gene expression appears to be confined to immediate early time and its gene products are localized to the Golgi complex as crescent shaped forms in the perinuclear cytoplasm.

• Korean Journal of Microbiology
• /
• v.29 no.5
• /
• pp.284-289
• /
• 1991

the nucleotide sequence of the 3' terminal 568 bases of the 18S rRNA gene from Mucor racemosus was determined. The 3' end of the structural gene was identified by comparison with the published sequence for the Saccharomyces cerevisiae gene. The M. racemosus gene was found to share 83.8% homology with that of S. cerevisiae and 71-81% homology with those of human, mouse, maize, Xenopus laevis and Tetrahymena thermophila. The known methylation sites in X. laevis and human were also highly conserved in M. racemosus and located within most conserved regions of 18S RNA gene throughout evolution.