• 생명과학회지
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• 제33권1호
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• pp.8-14
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• 2023

Peroxidasin (PXDN)은 촉매 도메인 외에도 세포외기질 모티프를 포함한 다양한 도메인을 가진 heme peroxidase로서, collagen IV (Col IV)에서 sulfilimine 가교를 형성하여 Col IV의 스캐폴드를 강화한다. 우리는 이전 논문에서 PXDN이 sulfilimine 가교 의존적인 기질 assembly를 통하여 내피세포 생존 및 성장 신호전달에 필요하다고 보고하였다. 이 연구에서는 내피세포에서의 PXDN 기능에 있어 peroxidase 활성의 필요성을 조사하였다. 첫번째로 peroxidase 도메인의 활성 부위에 존재하며 고도로 보존된 Q823과 D826을 각각 W823, E826으로 치환한 돌연변이체를 제작하였다. 이러한 돌연변이 단백질을 높게 발현하는 HEK293 클론을 분리하였고, 이들 세포를 무혈청 배지에서 24시간 배양하여 조건 배지를 확보하여 평가하였다. 조건 배지에 대해 비환원 조건으로 Western blot 분석을 실시하였을 때, 돌연변이 단백질은 삼량체를 형성하는 것으로 관찰되었고, proprotein convertase에 의해 야생형 PXDN처럼 절단되는 것을 확인하였다. 그러나, peroxidase 활성은 돌연변이 PXDN이 포함된 조건 배지에서 야생형 PXDN과는 대조적으로 관찰되지 않았다. 또한, sulfilimine 가교 형성 능력도 돌연변이 PXDN에서 소실되었음이 확인되었다. 이에 더하여, PXDN이 depletion된 내피세포에 돌연변이 PXDN이 포함된 조건배지를 가하였을 때, 야생형 PXDN 조건배지와 달리 증식을 촉진시키지 못함을 관찰하였다. 이러한 결과들은 PXDN의 peroxidase 활성이 sulfilimine 가교를 형성하여 내피세포 성장에 영향을 미침을 제안한다.

• Molecules and Cells
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• 제38권1호
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• pp.51-57
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• 2015

The Caenorhabditis elegans peroxidasins, PXN-1 and PXN-2, are extracellular peroxidases; pxn-2 is involved in muscle-epidermal attachment during embryonic morphogenesis and in specific axon guidance. Here we investigate potential roles of the other homologue of peroxidasin, pxn-1, in C. elegans. A pxn-1 deletion mutant showed high lethality under heat-stress conditions. Using a transcriptional GFP reporter, pxn-1 expression was observed in various tissues including neurons, muscles, and hypodermis. A translational fusion showed that PXN-1::GFP was secreted and localized in extracellular matrix, particularly along body wall muscles and pharyngeal muscles. Various neuronal developmental defects were observed in pxn-1 mutants and in pxn-1 over-expressing animals, including handedness, branching, breakage, tangling, and defasciculation. These results suggest that pxn-1, like other peroxidasins, plays an important role throughout development.

• 통합자연과학논문집
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• 제12권4호
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• pp.142-146
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• 2019

Peroxidasin is a unique member of peroxidase family in that it has extracellular matrix (ECM) motif as well as peroxidase activity. Peroxidasins are involved in consolidation the extracellular matrix during development and in innate immune defense. C. elegans has two functional peroxidasins, PXN-1 and PXN-2, and PXN-2 is known to contribute to innate immune system. However, it is not clear of PXN-1 function in innate immune system. Therefore, this study is focused on the function of PXN-1 and the relationship between PXN-1 and PXN-2 in innate defense system in C. elegans. When pxn-1 was knocked down by RNAi, the worm turned to be more resistant to pathogens, Staphylococcus aureus and Pseudomonas aeruginosa and the enhanced resistance was abolished in pxn-1pxn-2 double knock down. By contrast, pxn-2 knock down showed stronger susceptibility to the pathogens. These results suggest that pxn-2 can contribute the pathogen resistance and pxn-1 can suppress the pathogen resistance. To confirm the idea, overexpression experiments were performed. Overexpression of pxn-1 showed more susceptible to pathogens compared to the control and double overexpression of pxn-1pxn-2 overcame the susceptibility of pxn-1 overexpression to the pathogens. On the other hand, pxn-2 overexpression made the worm more resistant to the pathogens and the resistance was maintained in pxn-1pxn-2 double overexpression. The comparison of the susceptibilities to the bacterial pathogens in above mentioned constructs suggests that PXN-1 suppress the function of PXN-2 in defense against bacterial pathogens in Caenorhabditis elegans.