• Molecules and Cells
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• 제37권4호
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• pp.307-313
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• 2014

Cell migration requires a defined cell polarity which is formed by diverse cytoskeletal components differentially localized to the poles of cells to extracellular signals. Rap-GAP3 transiently and rapidly translocates to the cell cortex in response to chemoattractant stimulation and localizes to the leading edge of migrating cells. Here, we examined localization of truncated RapGAP3 proteins and found that the I/LWEQ domain in the central region of RapGAP3 was sufficient for posterior localization in migrating cells, as opposed to leading-edge localization of full-length Rap-GAP3. All truncated proteins accumulated at the leading edge of migrating cells exhibited clear translocation to the cell cortex in response to stimulation, whereas proteins localized to the posterior in migrating cells displayed no translocation to the cortex. The I/LWEQ domain appears to passively accumulate at the posterior region in migrating cells due to exclusion from the extended front region in response to chemoattractant stimulation rather than actively being localized to the back of cells. Our results suggest that posterior localization of the I/LWEQ domain of RapGAP3 is likely related to F-actin, which has probably different properties compared to newly formed F-actin at the leading edge of migrating cells, at the lateral and posterior regions of the cell.

• 생명과학회지
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• 제7권3호
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• pp.198-204
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• 1997

tyrosine 인산화효소계를 통한 신호전달은 신경의 발생과 연접환성조절에 중요한 역할을 한다. 흰쥐 소뇌의 연접후치밀질에 존재하는 tyrosine 함유 당백질들을 조사하기 위하여 immunoblot 분석을 한 결과, 소뇌 연접후치밀질의 전반적인 단백질조성은 전뇌와 비슷하였다. phosphotyrosine 특이성 항체로, immunobolot 한 결과 소뇌의 주된 tyrosine 인산화 단백질은 50 kD 크기의 새로운 단백질이었다. PSD-50로 명명한 이 단백질은 SDS-PAGE에서 $\alpha$CaMKII와 같은 위치에 이동하였다. 그러나 소뇌에는 전뇌에 비하여 적은량의 $\alpha$CaMKII가 존재함에도 불구하고 전뇌보다 더 강한 phosphotyrosine immunoblot signal을 보이는 것으로 보아 PSD-50는 아마도 $\alpha$CaMKII와는 다른 단백질로 추정된다.

• Radiation Oncology Journal
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• 제22권4호
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• pp.298-306
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• 2004

목적:. 방사선 감수성이 다른 마우스 조직에서 apoptosis 유도 수준을 확인하고 방사선 감수성에 관여 된 인자를 Proteomics를 통해서 확인한다. 대상 및 방법: C3H/HeJ 마우스에 10 Gy 방사선을 조사하고 8시간 후 비장과 간을 채취하여 apoptosis 유도 수준을 비교 분석하였다. 조직에서 단백질을 추출하여 2-dimension electrophoresis (2-DE)를 실시하였다. 2-DE에서 방사선에 의해 발현의 변화를 보이는 gel의 spot를 trypsin 처리하여 MALDI-TOF 측정한 후 Swiss-prot database를 통하여 단백질 을 동정하였다. 결과: Apoptosls index는 방사선 조사 후 비장 조직에서 $35.3{\pm}1.7{\%}$, 간조직은 $0.6{\pm}0.2{\%}$로 비장에 비해 간 조직이 낮게 나타났다. Proteomoics 결과에서 방사선 내성 조직인 간은 ROS대사에 관여되는 단백질인 glutathione Stransferase Pi, carbonic anhydrase, NADH dehydrogenase, peroxiredoxin VI, riken cDNA 등이 방사선 조사 후 증가되었고 apoptosis 관련된 단백질인 cytochrome c는 간과 비장 조직에서 확인되었다. 그러나 방사선 민감 조직인 비장에서는 방사선 조사 후 산화적 Stress에 관련된 단백질, apoptosis 관련 단백질, 신호 전달에 관련된 단백질, 면역반응, cell cycle, Ca 신호 전달, 대사 cycle에 관련된 단백질 등이 방사선에 관련하여 발현의 변화를 보여 주었다. 결론 : Apoptosis유도 수준이 다른 조직에서 apoptosis에 관련된 단백질과 redox에 관련된 단백질은 방사성 감수성 조절에 관련된 것으로 보인다.

• 대한치과보철학회지
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• 제44권1호
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• pp.73-84
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• 2006

The importance of soft tissue response to implant abutments has become one of the major issues in current implant dentistry. To date, numerous studies have emphasized on maintaining connective tissue barriers in quantity, as well as in quality fir the long term success of dental implants. The cells mainly consisting the soft tissue around dental implants are fibroblasts and epithelial cells. The mechanism of the fibroblasts adhesions to certain substrata can be explained by the 'focal adhesion' theory. On the other hand, epithelial cells adhere tn the substratum via hemidesmosomes. The typical integrin-mediated adhesions of cells to certain matrix are called 'cell-matrix adhsions'. The focal adhesion complex of fibroblasts, in relation to the cell-matrix adhsions, consists of the extracellular matrix(ECM) such as fibronectin, the transmembrane proteins such as integrins, the intracellular cytoplasmic proteins such as vinculin, talin, and more, and the cytoskeletal structures such as filamentous actin and microtubules. The mechanosensory function of integrins and focal adhesion complexes are considered to play a major role in the cells adhesion, migration, proliferation, differentiation, division, and even apoptosis. The '3-D matrix adhesions' defined by Cukierman et al. makes a promising future for the verification of the actual process of the cell-matrix adhesions in vivo and can be applied to the field of implant dentistry in relation to obtaining strong soft tissue attachment to the implant abutments.

• Parasites, Hosts and Diseases
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• 제33권3호
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• pp.155-164
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• 1995

Cyptosporidium parvum의 발달 단계별 actin과 myosin의 분포 위치를 면역황금염색법을 이용하여 관찰하였다. $Depomedrol^{\circledR}$을 ICR마우스에 피하주사하여 면역억제시킨 후 C. parvum이 발현된 마우스 회장을 잘라 LR gold로 포매하여 초박절편을 떴다. 일차항체로는 chickenbackmuscle actin과 bovine uterus myosin에 대한 rabbit polyclonal antibody를 사용하였고 이차항체로는 10 mm 크기의 황금입자가 결합된 goatanti-rabbit lgG를 반응시켰다 Uranylacetate와 leadcitrate로 염색한 후 투과전자현미경으로 관찰하였다 Trophozoite에서는 세포막에서 주로 actin과 myosin이 관찰되었고 feederorganelle 주위 세포질에는 actin이 분포하였다. Meront와 같이 활발히 분열하고 있는 단계에서는 세포막과 세포질 전체에 actin이 분포되어있었으며 myosin은 세포막에서만 소량 관찰되었다. 핵과 anlage of rhoptries 등은 두 단백질에 모두 염색되지 않았다. Macrogametocyte 에서는 amylopectin-lile bodies에서 actin과 myosin이 모두 관찰되었으나 wall forming bodies에서는 관찰되지 않았고 feederorganelle 주위 세포질 부분에서는 actin이 관찰되었다. Sporozoite를 포함하는 oocyst와 merozoite를 포함하는 meront에서는 세포막과 세포막사이에서 actin이 다수 관찰 되었으며 myosin은 소량 관찰되었다. Merozoites가 빠져나가 속이 비어있는 parasitophorous vacuole중에는 microspike를 형성한 것들이 종종 관찰되었고 이것이 좀더 길어져 마치 microvilli와 같이 보이는 경우도 있었으며 이러한 구조물에서도 actin이 다수 관찰되었다. 이상의 결과로 미루어 actin과 myosin은 세포막에 주로 분포하면서 C. parvum의 형태를 유지시키며 또한 세포막의 움직임을 조절하는 cytoskeletalproteiA으로서의 역할이 주된 작용일 것으로 생각되었다.

• 대한의생명과학회지
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• 제7권2호
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• pp.59-64
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• 2001

Nebulin is an unusually large actin-binding protein specific to the skeletal muscle of vertebrates. The correlation of nebulin size with thin filament length have led to the suggestion that nebulin acts as a molecular ruler for the length of thin filaments. An SH3 domain occupies the C terminus of nebulin, in the sarcomeric Z-disk and is preceded by a 120-residue stretch containing multiple putative phosphorylation sites. SH3 domain mediates protein-protein interaction involved in the subcellular localization of proteins, cytoskeletal organization and signal transduction. However the binding partner and physiological role of nebulin SH3 domains remains unknown. Using the yeast two-hybrid system, we identified supervillin, an actin-binding protein, as a nebulin SH3 domain-interacting protein. The SH3 domain of nebulin binds to the sequence encoding amino acids 977 to 1335 of supervillin. But the sequence encoding amino acids 977 to 1335 displays weaker binding than the sequence encoding amino acids 977 to 1788.

• Clinical and Experimental Pediatrics
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• 제48권6호
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• pp.580-587
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• 2005

New evidence is emerging that airway smooth muscle(ASM) may act as an immunomodulatory cell by providing pro-inflammatory cytokines and chemokines, polypeptide growth factors, extracellular matrix proteins, cell adhesion receptors and co-stimulatory molecules. ASM can promote the formation of the interstitial extracellular matrix, and potentially contribute to the alterations within the extracellular matrix in asthma. In addition, extracellular matrix components can alter the proliferative, survival, and cytoskeletal synthetic function of ASM cells through integrin-directed signaling. Increased ASM mass is one of the most important features of the airway wall remodeling process in asthma. Three different mechanisms may contribute to the increased ASM mass : cell proliferation, increased migration and decreased rate of apoptosis. The major signaling pathways of cell proliferation activated by ASM mitogens are those dependent on extracellular signal-regulated kinase and phosphoinositide 3'-kinase. The key signaling mechanisms of cell migration have been identified as the p38 mitogen-activated protein kinase and the p21-activated kinase 1 pathways. ASM cells contain ${\beta}2$-adrenergic receptors and glucocorticoid receptors. They may represent a key target for ${\beta}2$-adrenergic receptor agonist/corticosteroid interactions which have antiproliferative activity against a broad spectrum of mitogens.

• The Korean Journal of Physiology and Pharmacology
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• 제4권3호
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• pp.211-217
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• 2000

Paxillin is a regulatory component of the complex of cytoskeletal proteins that link the actin cytoskeleton to the plasma membrane. However, the role of paxillin during smooth muscle contraction is unclear. We investigated a possible role for the membrane-associated dense plaque protein paxillin in the regulation of contraction in rat aortic vascular smooth muscle. The tyrosine phosphorylation of paxillin, which was increased by norepinephrine, reached a peak level after 1 min stimulation and then decreased with time. However, norepinephrine induced a sustained contraction that reached a steady state 30 min after application. Pretreatment with tyrphostin, an inhibitor of tyrosine kinase, inhibited the tyrosine phosphorylation of paxillin and also the contraction stimulated by norepinephrine. Both inhibitions were concentration-dependent, and the degree of correlation between them was high. These results show that, in rat aortic smooth muscle, tyrosine kinase(s) activated by norepinephrine may phosphorylate the tyrosine residues of paxillin, thereby providing a source of regulation during vascular smooth muscle contraction.

• BMB Reports
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• 제33권3호
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• pp.263-267
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• 2000

We cloned $hda1^+$ (histone deacetylase 1) of fission yeast Schizosaccharomyces pombe. The hda1 of S. pombe was previously reported to encode for an active histone deacetylase (Rundlett et al., 1996; Olsson et al., 1998). The $hda1^+$ is phylogenetically related to the new open reading frame HOS2 of Saccharomyces cerevisiae and only shows a partial homology to the well-known histone deacetylase subclasses, RPD3 and HDA1. A single hda1 mRNA of 1.8 kb was detected at the same level in actively growing and nitrogen-starved cells. When highly over-expressed in S. pombe from an inducible promoter, $hda1^+$ inhibited cell proliferation and caused defects in morphology and cell division. The increased histone deacetylase activity was detected in hdar over-expressing cells. These results suggest that the Hda1p should function on the regulation of cell division possibly by (Allfrey, 1966) direct deacetylation of cytoskeletal (Wade et al., 1997) and cell division regulatory proteins, (Wolffe, 1997) or by controlling their gene expressions.

• Parasites, Hosts and Diseases
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• 제54권4호
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• pp.461-469
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• 2016

Giardia lamblia is a protozoan that causes diarrheal diseases in humans. Cytoskeletal structures of Giardia trophozoites must be finely reorganized during cell division. To identify Giardia proteins which interact with microtubules (MTs), Giardia lysates were incubated with in vitro-polymerized MTs and then precipitated by ultracentifugation. A hypothetical protein (GL50803_8405) was identified in the precipitated fraction with polymerized MTs and was named GlMBP1 (G. lamblia microtubule-binding protein 1). Interaction of GlMBP1 with MTs was confirmed by MT binding assays using recombinant GlMBP1 (rGlMBP1). In vivo expression of GlMBP1 was shown by a real-time PCR and western blot analysis using anti-rGlMBP1 antibodies. Transgenic G. lamblia trophozoites were constructed by integrating a chimeric gene encoding hemagglutinin (HA)-tagged GlMBP1 into a Giardia chromosome. Immunofluorescence assays of this transgenic G. lamblia, using anti-HA antibodies, revealed that GlMBP1 mainly localized at the basal bodies, axonemes, and median bodies of G. lamblia trophozoites. This result indicates that GlMBP1 is a component of the G. lamblia cytoskeleton.