• 제목/요약/키워드: Ras protein

검색결과 172건 처리시간 0.02초

Effects of Buckwheat on the Insulin Sensitivity, Protein Digestibility and Utility in Diabetic Rats

  • Park, Hyun-Ju;Lee, Kyung-Hea
    • Preventive Nutrition and Food Science
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    • 제3권4호
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    • pp.356-361
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    • 1998
  • An experiment was performed to determine if buckwheat intake would improve insulin sensitivity in in normal healthy ras and steptozoticin-induced diabetic Sprague-Dauley rats. For four weeks, rats were fed either corn starch as a cotnrol diet or buckwheat as an experimental diet. As a result, the insulin sensitivity and plasma glucose levels in normal rats were not significantly affected by buckwheat fedding. The insulin sensitivity was lower in diabetic rats than in normal rats(p<0.05). Buckwheat tends to decrease the final plasma glucose level and increase insulin sensitivity in diabetic rats, but there was no sifnificant difference. Another five-week experiment was conducted to determine protein digestibility and protein utility in normal healty rats ad streptozotocin-induced diabetic rats on a control diet or buckwheat diet. The diet composition in this experiment was the same as the preceeding experiment. In the cotnrol diet groups, the protein digestibility in diabetic rats was significantly lower than that in normal rats(p<0.05). Buckwheat reduced protein digestibility in both normal and disbetic rats(p<0.05). Interestingly, in buckwheat diet groups, protei digestibility in diabetic rats was similar to that in normal rats. Protein utility was significantly lower indiabetic rats than in normal rats. This phenomenon was observed as early as the first week of the feeding period. However, protein utility was not sifnificanlty altered in both normal and diabetic rats by buckwheat feeding. It follows that decreased protein digestibility and utility in diabetic rts are not further aggravated by buckwheat feeding, suggesting that buckwheat can be a feasible supplement food for the diabetic therapeutic diet.

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A Screening Method for Src Homology 3 Domain Binding Blockers Based on Ras Signaling Pathway

  • Ko, Woo-Suk;Yoon, Sun-Young;Kim, Jae-Won;Lee, Choong-Eun;Han, Mi-Young
    • BMB Reports
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    • 제30권5호
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    • pp.303-307
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    • 1997
  • Grb2, which is composed of a Src homology 2 (SH2) domain and two Src homology 3 (SH3) domains, is known to serve as an adaptor protein in signaling for Ras activation. Thus, a blocker of the Grb2 interactions with other proteins can be a potential candidate for an anticancer drug. In this study, we have developed a high throughput screening method for SH3 domain binding ligands and blockers. Firstly, we made and purified the glutathione S-transferase (GST)-fusion proteins with the Grb2 SH2 and SH3 domains, and the entire Grb2. This method measures the binding of a biotin-labeled oligopeptide, derived from a Grb2/SH3 binding motif in the hSos, to the GST-fusion proteins, which are precoated as glutathione S-transferase fusion protein on a solid phase. When $1\;{\mu}g$ of each fusion protein was used to coat the wells, both N- and C- terminal SH3 the domains as well as the whole of Grb2 were able to interact with the biotin-conjugated ligand peptide, while the SH2 domain and GST alone showed no binding affinity. Although N- and C- terminal SH3 domains showed an increase of binding to the ligand peptide in proportion to the amount of peptide, the GST fusion protein with Grb2 demonstrated much higher binding affinity. GST-Grb2 coating on the solid phase showed a saturation curve; 66 and 84% of the maximal binding was observed at 100 and 300 ng/$100\;{\mu}l$, respectively. This binding assay system was peptide sequence-specific, showing a dose-dependent inhibition with the unlabeled peptide of SH3 binding motif. Several other peptides, such as SH2 domain binding motifs and PTB domain binding motif, were ineffective to inhibit the binding to the biotin-conjugated ligand peptide. These results suggest that our method may be useful to screen for new anticancer drug candidates which can block the signaling pathways mediated by SH3 domain binding.

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사람 단핵구에서 결핵균에 의해 유도되는 CCL3 및 CCL4 발현에 대한 Phospholipase-Protein Kinase C-MEK-ERK 경로의 역할 분석 (The Phospholipase-Protein Kinase C-MEK-ERK Pathway is Essential in Mycobacteria-induced CCL3 and CCL4 Expression in Human Monocytes)

  • 양철수;송창화;정샛별;이길수;김수영;이지숙;신아름;오재희;권유미;김화중;박정규;백태현;조은경
    • IMMUNE NETWORK
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    • 제5권4호
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    • pp.237-246
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    • 2005
  • Background: Little information is available on the identification and characterization of the upstream regulators of the signal transduction cascades for Mycobacterium tuberculosis (M. tbc)-induced ERK 1/2 activation and chemokine expression. We investigated the signaling mechanisms involved in expression of CCL3 /MIP-1 and CCL4/MIP-1 in human primary monocytes infected with M. tbc. Methods: MAP kinase phosphorylation was determined using western blot analysis with specific primary antibodies (ERK 1/2, and phospho-ERK1/2), and the upstream signaling pathways were further investigated using specific inhibitors. Results: An avirulent strain, M. tbc H37Ra, induced greater and more sustained ERK 1/2 phosphorylation, and higher CCL3 and CCL4 production, than did M. tbc H37Rv. Specific inhibitors for mitogen-activated protein kinase (MAPK) kinase (MEK; U0126 and PD98059) significantly inhibited the expression of CCL3 and CCL4 in human monocytes. Mycobactetia-mediated expression of CCL3 and CCL4 was not inhibited by the Ras inhibitor manumycin A or the Raf-1 inhibitor GW 5074. On the other hand, phospholipase C (PLC) inhibitor (U73122) and protein kinase C (PKC)specific inhibitors ($G\ddot{o}6976$ and Ro31-8220) significantly reduced M. tbc-induced activation of ERK 1/2 and chemokine synthesis. Conclusion: These results are the first to demonstrate that the PLC-PKC-MEK-ERK, not the Ras-Raf-MEK-ERK, pathway is the major signaling pathway inducing M. tbc-mediated CCL3 and CCL4 expression in human primary monocytes.

Phosphorylation of SAV1 by mammalian ste20-like kinase promotes cell death

  • Park, Byoung-Hee;Lee, Yong-Hee
    • BMB Reports
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    • 제44권9호
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    • pp.584-589
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    • 2011
  • The mammalian ste20-like kinase (MST) pathway is important in the regulation of apoptosis and cell cycle and emerges as a novel tumor suppressor pathway. MST-induced phosphorylation of Salvador homolog 1 (SAV1), which is a scaffold protein, has not been evaluated in detail. We performed a mass spectrometric analysis of the SAV1 protein that was co-expressed with MST2. Phosphorylation was detected at Thr-26, Ser-27, Ser-36 and Ser-269. Although single or double mutations had little effects, the mutation of all four residues in SAV1 to Ala (SAV1-4A) had inhibitory effects on the MST pathway. MST2-mediated induction of SAV1-4A protein levels, SAV1-4A interaction with MST2 and the self-dimerization of SAV1-4A were weaker compared to those of wild-type SAV1. SAV1-4A inhibited MST2- and K-RasG12V-induced cell death of MCF7 cells. These results suggest that MST-mediated phosphorylation of four residues within SAV1 may be important in the induction of cell death by the MST pathway.

Solandelactone G: A Novel Inhibitor of Farnesyl Protein Transferase (FPTase), Isolated from the Hydroid Solanderia secunda

  • Jongheon Shin;Youngwan Seo;Park, Jung-Rae;Kwon, Byoung-Mog;Nam, Ji-Youn;Jeong, Tae-Sook;Bok, Song-Hae
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1995년도 춘계학술대회
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    • pp.63-63
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    • 1995
  • Farnesyl Protein Transferase (FPTase) catalyses a post-translational modification of Ras that is obligatory for the cell transforming activity of this oncogene protein. The screening of natural products to identify inhibitors of this enzyme as a potential anticancer agents, has led to the isolation of a novel lactone, from the hydroid Solanderia secunda. Solandelactone G has been isolated from the hydroid Solanderia secunda collected along the offshore of Jaejudo and Keomunde. The structure of the compound has been determined as cyclopropane containing C$\_$22/ fatty acid lactone on the basis of the combined spectral and chemical methods

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방사선조사후 백서소장점막에서 발생하는 신호전달체계에 관한 연구 (The Signal Transduction Mechanisms on the Intestinal Mucosa of Rat Following Irradiation)

  • 유정현;김성숙;이경자;이정식
    • Radiation Oncology Journal
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    • 제15권2호
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    • pp.79-95
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    • 1997
  • 목적 : 최근 신호전달체계에서 중요한 효소로 알려진 phosphollpase C(PLC) 동위효소들의 발현이 조직의 종류와 발달과정에 따라 특이한 양상을 보이고 $PLC-{\gamma}1$은 세포의 성장, 분화 및 증식에 중추적 역할을 하는 것으로 알려져 있다 방사선 조사 후 세포내 신호전달에 관한 연구도 최근 활발하여 소장 점막의 재생에 $PLC-{\gamma}$ 및 ras 암 유전자단백이 관여하고, 조직 손상에 protein kinase C(PKC)가 관여하는 등 연구들이 보고되었으나 이들의 연구가 단편적이며 아직 확실히 밝혀진 바가 없다. 본 연구는 백서의 소장에 방사선을 조사하여 PLC 동위효소, epidermal growth factor receptor(EGFR), ras 암유전자단백, 및 PKC와 같이 신호전달체계에 관여하는 물질들의 발현을 시간적으로 관찰하여 방사선에 의한 소장 조직의 손상 및 재생 기전을 밝히고자 하였다. 대상 및 방벌 실험동물로 암.수 구별없이 생후 4-5개월, 체중 250-3009의 백서(Spraque-Dawley) 60마리를 대상으로 하여 실험군으로 전신에 8Gy의 방사선을 조사하고 방사선 조사 후 1일, 3일, 5일, 7일,14일에 각각 10마리씩 희생시켜 소장을 적출하여 사용하였고, 정상대조군은 각 시기별로 2마리씩 사용하였다. 적출된 소장의 반은 즉시 얼려 PLC의 면역블로팅 및 phosphoinositide(PI) 가수분해 활성도 측정에 사용하였고, 나머지 반은 포르말린에 고정한 다음 파라핀에 포매하여 조직병리검색과 면역조직화학염색에 사용하였다. EGFH, ras 암유전자단백, PLC, PKC의 발현은 면역조직화학염색법으로 관찰하였다. 점막세포의 재생여부는 광학현미경상의 유사분열 수와 proliferating ceil nuclear antigen(PCNA) kit를 이용한 증식세포핵 수로 확인하였다. PLC는 $PLC-{\beta},\;-{\gamma},\;-{\delta}$ 발현을 모두 검색하였고, 각각 면역블로팅과 Pl 가수분해 활성도 측정으로 확인하였다. 결과 : 1) 조직병리학 소견상 방사선 조사에 의한 소장의 조직손상은 1일부터 관찰되어 3일까지 심하였고 재생은 3일과 5일에 현저하였다. 2) 면역조직화학염색 결과 $PLC-{\gamma}1$의 발현은 재생을 보이는 3일과 5일에 발현되었으며 5일째의 점막에서 가장 강하게 나타났다. $PLC-{\delta}1$은 방사선 조사 후 손상을 보이는 1일과 3일의 점막에서 강한 발현을 나타내었다. $PLC-{\beta}1$은 모든 실험군에서 발현되지 않았다. 면역블로팅 결과도 면역조직화학염색과 일치하는 결과를 보였다. 3) $PLC-{\gamma}1$의 활성도를 보기 위한 PI 가수분해 활성도 측정결과는 3일과 5일에 현저히 높은 수치를 보여 방사선 조사후 소장점막의 재생과정의 중요한 신호전달과정이 PLC-1이 관여하는 PI 가수분해에 의해 이뤄짐을 알 수 있었다. 4) ras 암유전자단백의 발현온 재생이 시작되는 3일부터 나타나 7일까지 지속되었고, EGFR 도 재생시기인 3일과 5일에 가장 강하게 나타났고 그 후 점차 감소하는 추세를 보였다. 한편 PKC는 발현이 미약했으나 증식지수가 높은 점막에 3일과 5일에 발현이 관찰되었다. 결론 : 방사선조사에 의한 소장점막조직의 손상 및 재생과정의 신호전달기전에 PLC의 신호전달체계에 관여하는 효소가 중요한 역할을 하며 특히 $PLC-{\gamma}1$과 ras암유전자단백, EGFR, PKC는 방사선조사 후 공장점막세포의 재생기전에 주로 발현되어 재생과정과 관련된 신호전달기전에 관여함을 나타내었다. $PLC-{\delta}$은 방사선 조사 후 세포의 손상시기에 강한 발현을 보여 특히 손상과정과 관련된 신호전달기전에 관여함을 추측할 수 있었다. $PLC-{\beta}1$의 발현은 모든 실험군에서 음성인 소견을 보여 방사선조사 후 소장점막의 세포손상 및 재생과정에서 $PLC-{\beta}1$과 관련된 신호전달체계는 관여하지 않음을 알 수 었었다. 그러나, 이러한 신호전달체계의 기전을 구체적으로 밝히기 위해서는 추후 지속적인 연구가 필요하다고 사료된다.

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자연산 산삼 증류약침의 혈맥주입 전.후 혈장의 Proteom 분석 (Analysis of Serum proteom before and after Intravenous Injection of wild ginseng herbal acupuncture)

  • 강태식;이선구;권기록
    • 대한약침학회지
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    • 제7권3호
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    • pp.5-25
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    • 2004
  • Objectives : To observe changes in the serum proteins before and after intravenous injection of wild ginseng herbal acupuncture. Methods : Blood was collected before and after the administration of wild ginseng herbal acupuncture and only the serum was centrifuged. Then differences in the spots on the scanned image after running 2-Dimensionl electrophoresis were located and conducted mass analysis and protein identification. Results : Following results were obtained from the comparative analysis of serum proteins before and after the administration of wild ginseng herbal acupuncture. 1. 28 spots were identified before and after the administration. 2. In confirming manifestation degree, spots with more than two-times increase were 204, 803, 1505, 2205, 3105, 7104, 9001 spots, with more than one-time increase were 1101, 1302, 2013, 3009, 3010, 4002, 4009, 6706, 7103, 8006, 8101, and spots with decrease were 205, 801, 3205, 5202, 6105. 3. After conducting protein identification, proteins 205, 804, 1302, 4009, 6105, 6106 are unidentified yet, and 1101 is unnamed protein. Protein 204 is identified as complement receptor CR2-C3d, 801 as YAP1 protein, 803 as antitrypsin polymer, 1505 as PRO0684, 2013 and 3010 as proapolipoprotein, 2205 as USP48, 2403 as vitamin D binding protein, 3009 as complement component 4A preprotein, 3105 as immunoglobulin lambda chain, 3205 as transthyretin, 4002 as Ras-related protein Ral-A, 4204 as beta actin, 5202 and 7104 as apolipoprotein L1, 6704 as alpha 2 macroglobulin precursor, 7103 as complement component 3 precursor, 8006 as testis-specific protein Y, 8101 as Transferrin, 9001 as(Alpha-Oxy, Beta-(C112g)deoxy) T-State Human Hemoglobin, and 9003 as human hemoglobin. 4. Immune protein CR2-C3d, which acts against microbes and pathogenic organisms, and Antitrypsin(803), which is secreted with inflammatory response in the lungs, were increased by more than 200% after the administration of herbal acupuncture. 5. Immunoglobulin lambda chain(3105), Alpha-Oxy, Beta-(C112g)deoxy T-State Human Hemoglobin(9001), and human hemoglobin(9003) were increased by more than two-times after the administration of herbal acupuncture. 6. Proapolipoprotein(2013, 3010) and apolipoprotein(7104), key components of the HDL-cholesterol which plays an important role in preventing arteriosclerosis, were increased after the administration of herbal acupuncture. 7. Vitamin D binding protein(DBP, 2403), protecting the lung at the time of inflammatory response, was increased after the administration of herbal acupuncture. 8. Transthyretin(TTR, 3205), which is the main protein causing familial aimyloid polyneuropathy(FAP), was decreased after the administration of herbal acupuncture. 9. Ras-related protein Ral-A(4002) that controls phospholipid metabolism, cytoskeletal formation, and membrane traffic, was increased after the administration of herbal acupuncture. 10. Testis-specific protein Y(8006), which takes part in determination of the gender, was increased by more than two-times after the administration of herbal acupuncture. 11. Transferrin(8101), T-State Human Hemoblobin(9001), and Human Hemoblobin(9003) which balances the iron level in the body, were increased after the administration of herbal acupuncture. Conousion : Above results support the notion that intravenous injection of cultivated wild ginseng herbal acupuncture induce changes in serum proteins and this research can be a pioneer work in finding biomarkers.

주식에 첨가된 간식이 흰쥐의 체내대사에 미치는 영향 (Dual Effects of Calorie and Protein Restricted Diet Supplemented by Sugar on Albino Rat)

  • 이현경;김숙희
    • Journal of Nutrition and Health
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    • 제6권4호
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    • pp.23-36
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    • 1973
  • This study was designed to compare the effect of dietary intakes on different quality protein & levels of caloric consumption supplemented by sugar at the level of 26% of total caloric intakes. 30 males and same number of females of Albino rats, aged 30-40 days were devided into following six groups, 5 rats each. ACO Group: Ad libitum, Casein, no sugar group ACS Group: Ad libitum, Casein, 26% sugar supplemented group RBO Group: 50% restriction,Bean, no sugar group RBS Group: 50% restriction, Bean, 26% sugar supplemented group RAO Group: 50% restriction, Anchovy, no sugar group RAS Group: 50% restriction, Anchovy, 26% sugar supplemented group The rats were kept in individual cage and given 6 different diet for 12 weeks. The result of this study were elucidated as follow. Body weight gained and organ weight showed no significant differences between sugar supplemented group and the others. It was noteworthy that the shrinkage of female sex organ supplemented by sugar in the diet showed lower degree than that of compared groups in this study. In other word, degree of shrinkage due to protein-caloric restriction was decreased by sugar supplementation. Nitrogen Metabolism and total nitrogen retention were not observed any significant differences between sugar supplemented group and the others. Dental caries showed higher incidence for sugar supplemented groups. Hematology and bone growth showed no differences in this study. The similar results on the metabolic effects concerned the above view Points were obtained in the different protein groups such as bean & anchovy as protein sources in the diet. Caloric restriction Produced a lower growth-rate, lower body weight and poorer long bone growth. But composition of bone ash, concentration of nitrogen, calcium and blood glucose, liver fats and liver water content maintenanced at the same levels of standard group.

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Tumor angiogenesis에 있어서 RLIP76의 중요성 (RalA-binding Protein 1 is an Important Regulator of Tumor Angiogenesis)

  • 이승형
    • 생명과학회지
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    • 제24권5호
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    • pp.588-593
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    • 2014
  • 본 논문은 RLIP76 단백질이 암, 종양 혈관 신생 및 그 치료에 미치는 중요성을 보고함에 있다. 암의 연구에 있어서, 종양의 혈관 신생을 억제시키는 인자와 영향을 끼치는 인자를 밝혀내는 것은 암의 억제와 치료를 위한 분자 생물학적 기전에 중대한 영향을 미친다. 최근 연구에서, RLIP76 단백질이 혈관 신생에 영향을 끼치는 역할을 발견하였다. RLIP76 제거 마우스의 종양은 일반 종양과 비교하여 혈관의 크기가 작으며, 가늘고, 그 혈관의 수가 적고 길이가 짧은 것으로 보고되고 있다. 게다가, Matrigel plugs을 이용한 혈관 신생 실험에서, RLIP76이 제거된 마우스에서는 혈관 생성이 억제 되었으나, 일반 마우스에서는 혈관이 생성되었다. 또한, 혈관세포를 이용한 in vitro 실험에 있어서, proliferation, migration 및 cord formation 모두가 RLIP76에 의해서 조절되었다. 일반적으로 RLIP76은 대부분의 인간 조직과 종양에서 발현되며, 약의 저항 기전 연구에 이용되고 있기도 한다. 또한, 이RLIP76은 small GTPase R-Ras와 상호작용을 통하여 세포 spreading 및 migration에 관여하고 있다. 이러한 결과는 RLIP76와 암 연구의 중요성을 보고하고 있으며, 혈관 세포의 기능의 기전 및 종양의 혈관 신생을 위한 RLIP76 단백질의 중요성을 알리고 있고, RLIP76의 추가적인 연구를 통하여 종양의 혈관 신생의 기전을 밝히는 것이 필요함을 제안하는 바이다.

The SH3 Domain of Phospholipase C-${\gamma}1$ Associates with Shc

  • Kim, Myung-Jong;Hwang, Jong-Ik;Chang, Jong-Soo;Ryu, Sung-Ho;Suh, Pann-Ghill
    • BMB Reports
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    • 제32권2호
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    • pp.119-126
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    • 1999
  • The SH3 domain of PLC-${\gamma}1$ has been known to induce DNA synthesis. However, little is known about the putative effector proteins that associate with the domain. In this report, we provide evidence that the SH3 domain of PLC-${\gamma}1$ associates with Shc, which has been implicated in the activation of p21Ras in response to many growth factors. The association between Shc and PLC-${\gamma}1$ is enhanced either by v-Src-induced transformation or EGF-stimulation in vivo and in vitro. Furthermore, from transient expression studies with COS-7 cells, we show that the SH3 domain of PLC-${\gamma}1$ is required for association with Shc in vivo, whereas tyrosyl phosphorylation of PLC-${\gamma}1$ is not. Taken together, we suggest that Shc might be involved in the PLC-${\gamma}1$-mediated signaling pathway.

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