• BMB Reports
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• 제29권6호
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• pp.549-554
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• 1996

Phosphoinositide turnover in response to platelet-derived growth factor, epidermal growth factor, and bradykinin was evaluated in NIH 3T3 cells. Platelet-derived growth factor and bradykinin induced a significant increase in incorporation of $^{32}P$ into phosphatidylinositol (PI), phosphatidylinositol 4-monophosphate (PIP), and phosphatidylinositol 4.5-bisphosphate ($PIP_2$) in serum-starved NIH 3T3 cells. However, epidermal growth factor increased incorporation of $^{32}P$ into these phosphoinositides by only a small amount. Stimulation with platelet-derived growth factor, not bradykinin, caused a rapid elevation of PI and PIP kinase activities that were maximally activated within 10 min. The maximal levels of their elevation in cells with plateletderived growth factor stimulation were 3.2-fold for PI kinase, and 2.1-fold for PIP kinase. Short term pretreatment of NIH 3T3 cells with phorbol 12-myristate 13-acetate, activator of protein kinase C. caused an approximately 60% decrease in platelet-derived growth factor-induced PI kinase activities, indicating the feedback regulation of phosphoinositide turnover by protein kinase C. These results suggest that although the enhancement of phosphoinositide turnover is a rapidly occurring response in platelet-derived growth factor- or bradykinin-stimulated NIH 3T3 cells, phosphoinositide kinases may be associated with initial signal transduction pathway relevant to platelet-derived growth factor but not to bradykinin.

• BMB Reports
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• 제47권7호
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• pp.361-368
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• 2014

Lipid components in biological membranes are essential for maintaining cellular function. Phosphoinositides, the phosphorylated derivatives of phosphatidylinositol (PI), regulate many critical cell processes involving membrane signaling, trafficking, and reorganization. Multiple metabolic pathways including phosphoinositide kinases and phosphatases and phospholipases tightly control spatio-temporal concentration of membrane phosphoinositides. Metabolizing enzymes responsible for PI 4,5-bisphosphate (PI(4,5)P2) production or degradation play a regulatory role in Toll-like receptor (TLR) signaling and trafficking. These enzymes include PI 4-phosphate 5-kinase, phosphatase and tensin homolog, PI 3-kinase, and phospholipase C. PI(4,5)P2 mediates the interaction with target cytosolic proteins to induce their membrane translocation, regulate vesicular trafficking, and serve as a precursor for other signaling lipids. TLR activation is important for the innate immune response and is implicated in diverse pathophysiological disorders. TLR signaling is controlled by specific interactions with distinct signaling and sorting adaptors. Importantly, TLR signaling machinery is differentially formed depending on a specific membrane compartment during signaling cascades. Although detailed mechanisms remain to be fully clarified, phosphoinositide metabolism is promising for a better understanding of such spatio-temporal regulation of TLR signaling and trafficking.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2003년도 추계 총회 및 학술대회
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• pp.38-39
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• 2003

• 대한약리학회지
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• 제30권3호
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• pp.331-336
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• 1994

본 연구의 목적은 광 유도에 의한 nitric oxide (PIANO)유리가 혈관이완에 대해 cyclic GMP (cGMP)가 관여하는 지의 여부와 아울러 ${\alpha}$-수용체를 통한 수축에 PIANO가 어떻게 작용하는 지를 파악하고자 하였다. In vitro 실험에서 흰쥐의 대동맥을 준 최고농도의 phenylephrine (PE)으로 수축시킨 후 nitric oxide 생성을 변화시키는 약물이나 광민감성 (photosensitizing) 약물에 대한 반응을 등장력 변화로 기록하였다. PIANO에 의한 혈관이완은 광노출 강도와 기간 및 광민감성 약물농도에 비례하여 증가하였고 cGMP의 증가를 수반하였다. PE에 의해 증대되는 phosphatidylinositide(PI) 전환은 PIANO에 의해 억제되었다. 이상의 결과는 cGMP의 증가로 인해 PIANO에 의한 혈관이완이 일어나며 ${\alpha}$-아드레날성 수용체 자극에 의한 PI 전환의 억제현상은 cGMP 증가의 결과로 생각할 수 있다. 결론적으로 PIANO에 의한 혈관이완은 cGMP의 증가로 인함을 확인할 수 있었다.