http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Hana CHO (검색결과 212 건)
- 무료
- 기관 내 무료
- 유료
-
-
Cho, Hana,Kim, Yeon A,Ho, Won-Kyung Korean Society for Molecular Biology 2006 Molecules and cells Vol.22 No.1
<P>Phosphoinositides are critical regulators of ion channel and transporter activity. There are multiple isomers of biologically active phosphoinositides in the plasma membrane and the different lipid species are non-randomly distributed. However, the mechanism by which cells impose selectivity and directionality on lipid movements and so generate a non-random lipid distribution remains unclear. In the present study we investigated which structural elements of phosphoinositides are responsible for their subcellular location and movement. We incubated phosphatidylinositol (PI), phosphatidylinositol 4-monophosphate (PI(4)P) and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) with short or long acyl chains in CHO and HEK cells. We show that phosphate number and acyl chain length determine cellular location and translocation movement. In CHO cells, PI(4,5)P2 with a long acyl chain was released into the cytosol easily because of a low partition coefficient whereas long chain PI was released more slowly because of a high partition coefficient. In HEK cells, the cellular location and translocation movement of PI were similar to those of PI in CHO cells, whereas those of PI(4,5)P2 were different; some mechanism restricted the translocation movement of PI(4,5)P2, and this is in good agreement with the extremely low lateral diffusion of PI(4,5)P2. In contrast to the dependence on the number of phosphates of the phospholipid head group of long acyl chain analogs, short acyl chain phospholipids easily undergo translocation movement regardless of cell type and number of phosphates in the lipid headgroup.</P>
-
Hana Cho,Jae-Rin Lee,Jong-Yoon Lee,김현지,Myong-Joon Hahn,Jong-Sun Kang 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-
Chloride intracellular channel 1 (CLIC1) is a promising therapeutic target in cancer due to its intrinsic characteristics; it is overexpressed in specific tumor types and its localization changes from cytosolic to surface membrane depending on activities and cell cycle progression. Ca2+ and reactive oxygen species (ROS) are critical signaling molecules that modulate diverse cellular functions, including cell death. In this study, we investigated the function of CLIC1 in Ca2+ and ROS signaling in A549 human lung cancer cells. Depletion of CLIC1 via shRNAs in A549 cells increased DNA double-strand breaks both under control conditions and under treatment with the putative anticancer agent chelerythrine, accompanied by a concomitant increase in the p-JNK level. CLIC1 knockdown greatly increased basal ROS levels, an effect prevented by BAPTA-AM, an intracellular calcium chelator. Intracellular Ca2+ measurements clearly showed that CLIC1 knockdown significantly increased chelerythrine-induced Ca2+ signaling as well as the basal Ca2+ level in A549 cells compared to these levels in control cells. Suppression of extracellular Ca2+ restored the basal Ca2+ level in CLIC1-knockdown A549 cells relative to that in control cells, implying that CLIC1 regulates [Ca2+]i through Ca2+ entry across the plasma membrane. Consistent with this finding, the L-type Ca2+ channel (LTCC) blocker nifedipine reduced the basal Ca2+ level in CLIC1 knockdown cells to that in control cells. Taken together, our results demonstrate that CLIC1 knockdown induces an increase in the intracellular Ca2+ level via LTCC, which then triggers excessive ROS production and consequent JNK activation. Thus, CLIC1 is a key regulator of Ca2+ signaling in the control of cancer cell survival.
-
Cho, Hana,Han, Sisu,Choe, Junho,Park, Seung Gu,Choi, Sun Shim,Kim, Yoon Ki Oxford University Press 2013 Nucleic acids research Vol.41 No.2
<P>In mammals, nonsense-mediated mRNA decay (NMD) functions in post-transcriptional gene regulation as well as mRNA surveillance. A key NMD factor, Upf1, becomes hyperphosphorylated by SMG1 kinase during the recognition of NMD substrates. Hyperphosphorylated Upf1 interacts with several factors including SMG5, SMG6, SMG7 and PNRC2 to trigger rapid mRNA degradation. However, the possible cross-talk among these factors and their selective use during NMD remain unknown. Here, we show that PNRC2 is preferentially complexed with SMG5, but not with SMG6 or SMG7, and that downregulation of PNRC2 abolishes the interaction between SMG5 and Dcp1a, a component of the decapping complex. In addition, tethering experiments reveal the function of Upf1, SMG5 and PNRC2 at the same step of NMD and the requirement of SMG6 for Upf1 for efficient mRNA degradation. Intriguingly, microarray results reveal the significant overlap of SMG5-dependent NMD substrates more with PNRC2-dependent NMD substrates than with SMG7-dependent NMD substrates, suggesting the functional dominance of SMG5–PNRC2, rather than SMG5–SMG7, under normal conditions. The results provide evidence that, to some extent, endogenous NMD substrates have their own binding preference for Upf1-interacting adaptors or effectors.</P>
-
Cho, Hana,Hong, Kiryong,Strader, Matthew L.,Lee, Jae Hyuk,Schoenlein, Robert W.,Huse, Nils,Kim, Tae Kyu American Chemical Society 2016 Inorganic Chemistry Vol.55 No.12
<P>We present a time-resolved X-ray spectroscopic study of the structural and electronic rearrangements of the photocatalyst Mn-2(CO)(10) upon photodeavage of the metal-metal bond. Our study of the manganese K-edge fine structure reveals details of both the molecular structure and valence charge distribution of the photodissociated radical product. Transient X-ray absorption spectra of the formation of the Mn(CO)(5) radical demonstrate surprisingly small structural modifications between the parent molecule and the resulting two identical manganese monomers. Small modifications of the local valence charge distribution are decisive for the catalytic activity of the radical product. The spectral changes reflect altered hybridization of metal-3d, metal-4p, and ligand-2p orbitals, particularly loss of interligand interaction, accompanied by the necessary spin transition due to radical formation. The spectral changes in the manganese pre- and main-edge region are well-reproduced by time-dependent density functional theory and ab initio multiple scattering calculations.</P>
-
Cho, Hana,Cho, Young-Woo,Kang, Sun-Woong,Kwak, Mi-Kyoung,Huh, Kang Moo,Bae, You Han,Kang, Han Chang American Chemical Society 2017 MOLECULAR PHARMACEUTICS Vol.14 No.3
<P>The clinical application of intracellular gene delivery via nanosized carriers is hindered by intracellular multistep barriers that limit high levels of gene expression. To solve these issues, four different intracellular or external stimuli that can efficiently activate a gene carrier, a gene, or a photosensitizer (pheophorbide A [PhA]) were assessed in this study. The designed nanosized polymeric gene complexes were composed of PhA-loaded thiol-degradable polycation (PhA@RPC) and cytomegalovirus (CMV) promoter-equipped pDNA. After cellular internalization of the resulting PhA@ RPC/pDNA complexes, the complexes escaped endosomal sequestration, owing to the endosomal pH-induced endosomolytic activity of RPC in PhA@RPC. Subsequently, intracellular thiol-mediated polycation degradation triggered the release of PhA and pDNA from the complexes. Late exposure to light (for example, 12 h post-treatment) activated the released PhA and resulted in the production of reactive oxygen species (ROS). Intracellular ROS successively activated NF-kappa B, which then reactivated the CMV promoter in the pDNA. These sequential, stimuli-responsive chemical and biological reactions resulted in high gene expression. In particular, the time-point of light exposure was very significant to tune efficient gene expression as well as negligible cytotoxicity: early light treatment induced photochemical internalization but high cytotoxicity, whereas late light treatment influenced the reactivation of silent pDNA via PhA-generated ROS and activation of NF-kappa B. In conclusion, the quadruple triggers, such as pH, thiol, light, and ROS, successively influenced a gene carrier (RPC), a photosensitizer, and a genetic therapeutic, and the tempo-spatial activation of the designed quadruple stimuli-activatable nanosized gene complexes could be potential in gene delivery applications.</P>
-
-
Receptor-mediated regulation of ion channels by PIP₂
Cho, Hana,Cui, Shan Yu,Yun, Jin-Young,Ho, Wonkyoung 이화여자대학교 세포신호전달연구센터 2008 고사리 세포신호전달 심포지움 Vol. No.10
Phosphatidylinositol 4,5-bisphosphate(PIP₂) is well known as a central molecule in the phosphoinositide cycle, by serving as the precursor of important signaling molecules such as inositol trisphosphate(IP₃), diacylglycerol(DAG) or phosphatidylinositol 3,4,5-trisphosphate(PIP₃). Recently, it was shown that PIP₂ is not just a precursor, but also exerts a direct role in the regulation or various ion channels, including G protein-gated inward rectifying K^(+)(GIRK) channels. We investigated whether receptor stimulation induced changes in membrane PIP₂ concentration can regulate GIRK channel activities. In cardiac myocytes, endothelin-1 and prostaglandin-F2α, phenylephrine caused inhibition of GIRK currents, and this inhibition was further potentiated by wortmannin(an inhibitor of phosphatidylinositol kinase) and attenuated by addition of PIP₂ in the pipette solutions. These results suggest that these agonists inhibit GIRK currents via PIP₂ depletion. In contrast, stimulation of bradykinin receptors or M₁/M₃ muscarinic receptors had no effect on GIRK channels. To investigate the mechanism of receptor specificity, we examined whether the activation of GqPCRs induces localized PIP₂ depletion. When we applied endothelin-1 to the bath, GIRK channel activities recorded in cell-attached patches were not changed, implying that PIP₂ signal is not diffusible but is a localized signal. To test this possibility, we directly measured lateral diffusion by introducing fluorescence-labeled phosphoinositides to a small area of the membrane with patch pipettes. After pipettes were attached, phosphatidylinositol 4-monophosphate or phosphatidylinositol diffused rapidly to the entire membrane, whereas PIP₂ was confined to the membrane patch inside the pipette. The confinement of PIP₂ was disrupted after cytochalasin D treatment, suggesting that the cytoskeleton is responsible for the low mobility of PIP₂. Taken together, it was concluded that various GqPCRs inhibit GIRK currents in a receptor- specific manner and this receptor specificity is caused by the low mobility of PIP₂ and the spatial proximity between GqPCRs and target protein.
-
Cho, Hana,Strader, Matthew L.,Hong, Kiryong,Jamula, Lindsey,Gullikson, Eric M.,Kim, Tae Kyu,de Groot, Frank M. F.,McCusker, James K.,Schoenlein, Robert W.,Huse, Nils The Royal Society of Chemistry 2012 Faraday discussions Vol.157 No.-
<P>Ultrafast excited-state evolution in polypyridyl Fe(<SMALL>II</SMALL>) complexes is of fundamental interest for understanding the origins of the sub-ps spin-state changes that occur upon photoexcitation of this class of compounds as well as for the potential impact such ultrafast dynamics have on incorporation of these compounds in solar energy conversion schemes or switchable optical storage technologies. We have demonstrated that ground-state and, more importantly, ultrafast time-resolved X-ray absorption methods can offer unique insights into the interplay between electronic and geometric structure that underpins the photo-induced dynamics of this class of compounds. The present contribution examines in greater detail how the symmetry of the ligand field surrounding the metal ion can be probed using these X-ray techniques. In particular, we show that steady-state K-edge spectroscopy of the nearest-neighbour nitrogen atoms reveals the characteristic chemical environment of the respective ligands and suggests an interesting target for future charge-transfer femtosecond and attosecond spectroscopy in the X-ray water window.</P>
-
Cho, Hana,Kim, Kyoung Mi,Kim, Yoon Ki Elsevier 2009 Molecular cell Vol.33 No.1
<P><B>Summary</B></P><P>Nonsense-mediated mRNA decay (NMD) is the best-characterized mRNA surveillance mechanism by which aberrant mRNAs harboring premature termination codons are degraded before translation. However, to date, how NMD machinery recruits the general decay complex to faulty mRNAs and degrades those mRNAs remains unclear. Here we identify human proline-rich nuclear receptor coregulatory protein 2 (PNRC2) as a Upf1- and Dcp1a-interacting protein. Downregulation of PNRC2 abrogates NMD, and artificially tethering PNRC2 downstream of a normal termination codon reduces mRNA abundance. Accordingly, PNRC2 preferentially interacts with hyperphosphorylated Upf1 compared with wild-type Upf1 and triggers movement of hyperphosphorylated Upf1 into processing bodies (P bodies). Our observations suggest that PNRC2 plays an essential role in mammalian NMD, mediating the interaction between the NMD machinery and the decapping complex, so as to target the aberrant mRNA-containing RNPs into P bodies.</P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
