• Title/Summary/Keyword: PTP

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Immunomodulatory Effects of Euglena gracilis Extracts (Euglena gracilis 추출물의 면역조절 및 생리활성 분석)

  • Yu, Sun Nyoung;Park, Bo Bae;Kim, Ji Won;Hwang, You Lim;Kim, Sang Hun;Kim, Sunah;Lee, Taeho;Ahn, Soon Cheol
    • Journal of Life Science
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    • v.31 no.2
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    • pp.183-191
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    • 2021

  • Euglena gracilis is a microalga of great biotechnological interest that can create high levels of bioactive compounds, such as tocopherol, paramylon, and folic acid. The objective of this study was to investigate the biological activities of extracts from E. gracilis, especially those focused on immunological activity. E. gracilis biomass was extracted with hot water (HWE) and the remaining pellet was continuously extracted with methanol (HWME). First, we examined the effect of two extracts from E. gracilis on the production of nitric oxide (NO) and the expression of pro-inflammation cytokines, including IL-1β, IL-6, and TNF-α in murine macrophage RAW 264.7 cells. HWE treatment dose-dependently increased the production of IL-1β and TNF-α. On the other hand, treatment with HWME significantly decreased the generation of NO and pro-inflammatory cytokines (IL-6 and TNF-α) in lipopolysaccharide (LPS)-stimulated macrophage cells. In addition, other biological activities of the extracts were further analyzed: α-glucosidase inhibition, protein tyrosine phosphatase (PTP1B) inhibition, tyrosinase inhibition, xanthine oxidase (XO) inhibition, and angiotensin-converting enzyme (ACE) inhibition. Analysis of these biological activities showed that HWE has more inhibitory effects than HWME against α-glucosidase, tyrosinase, and XO agents. However, the inhibition of PTP1B and ACE with HWME were higher than with HWE. Taken together, the results suggested that E. gracilis possesses various biological activities―especially immunological capabilities―through regulation of cytokine production. Therefore, E. gracilis extract may be potentially useful for food material with immune-regulating effects.

  • https://doi.org/10.5352/JLS.2021.31.2.183 인용 PDF KSCI HTML

Molecular Analysis of the Interaction between Human PTPN21 and the Oncoprotein E7 from Human Papillomavirus Genotype 18

  • Lee, Hye Seon;Kim, Min Wook;Jin, Kyeong Sik;Shin, Ho-Chul;Kim, Won Kon;Lee, Sang Chul;Kim, Seung Jun;Lee, Eun-Woo;Ku, Bonsu
    • Molecules and Cells
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    • v.44 no.1
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    • pp.26-37
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    • 2021

  • Human papillomaviruses (HPVs) cause cellular hyperproliferation-associated abnormalities including cervical cancer. The HPV genome encodes two major viral oncoproteins, E6 and E7, which recruit various host proteins by direct interaction for proteasomal degradation. Recently, we reported the structure of HPV18 E7 conserved region 3 (CR3) bound to the protein tyrosine phosphatase (PTP) domain of PTPN14, a well-defined tumor suppressor, and found that this intermolecular interaction plays a key role in E7-driven transformation and tumorigenesis. In this study, we carried out a molecular analysis of the interaction between CR3 of HPV18 E7 and the PTP domain of PTPN21, a PTP protein that shares high sequence homology with PTPN14 but is putatively oncogenic rather than tumor-suppressive. Through the combined use of biochemical tools, we verified that HPV18 E7 and PTPN21 form a 2:2 complex, with a dissociation constant of 5 nM and a nearly identical binding manner with the HPV18 E7 and PTPN14 complex. Nevertheless, despite the structural similarities, the biological consequences of the E7 interaction were found to differ between the two PTP proteins. Unlike PTPN14, PTPN21 did not appear to be subjected to proteasomal degradation in HPV18-positive HeLa cervical cancer cells. Moreover, knockdown of PTPN21 led to retardation of the migration/invasion of HeLa cells and HPV18 E7-expressing HaCaT keratinocytes, which reflects its protumor activity. In conclusion, the associations of the viral oncoprotein E7 with PTPN14 and PTPN21 are similar at the molecular level but play different physiological roles.

  • https://doi.org/10.14348/molcells.2020.0169 인용 PDF KSCI