• 제목/요약/키워드: Transmembrane Domain

검색결과 129건 처리시간 0.026초

Identification and Characterization of Putative Integron-Like Elements of the Heavy-Metal-Hypertolerant Strains of Pseudomonas spp.

  • Ciok, Anna;Adamczuk, Marcin;Bartosik, Dariusz;Dziewit, Lukasz
    • Journal of Microbiology and Biotechnology
    • /
    • 제26권11호
    • /
    • pp.1983-1992
    • /
    • 2016
  • Pseudomonas strains isolated from the heavily contaminated Lubin copper mine and Zelazny Most post-flotation waste reservoir in Poland were screened for the presence of integrons. This analysis revealed that two strains carried homologous DNA regions composed of a gene encoding a DNA_BRE_C domain-containing tyrosine recombinase (with no significant sequence similarity to other integrases of integrons) plus a three-component array of putative integron gene cassettes. The predicted gene cassettes encode three putative polypeptides with homology to (i) transmembrane proteins, (ii) GCN5 family acetyltransferases, and (iii) hypothetical proteins of unknown function (homologous proteins are encoded by the gene cassettes of several class 1 integrons). Comparative sequence analyses identified three structural variants of these novel integron-like elements within the sequenced bacterial genomes. Analysis of their distribution revealed that they are found exclusively in strains of the genus Pseudomonas.

Screening of cDNAs Encoding Secreted and Membrane Proteins in the Nervous System of Marine Snail Aplysia kurodai

  • Kim, Min-Jeong;Chang, Deok-Jin;Lim, Chae-Seok;Park, Woo-Jin;Kaang, Bong-Kiun
    • Animal cells and systems
    • /
    • 제7권2호
    • /
    • pp.133-137
    • /
    • 2003
  • Secreted proteins and membrane proteins play key roles in the formation, differentiation, and maintenance of multicellular organisms. In this study, we undertook to characterize these protein types in the central nervous system of the marine snail Aplysia kurodai using a yeast-based signal sequence trap method. One hundred and three cDNA clones were obtained by screening 300,000 clones from the signal sequence trap cDNA library. Of these, twelve were identical to previously identified Aplysia genes, 19 were related to known proteins in other organisms, and 54 clones were novel. These 54 new genes had high signal peptide scores or were found likely to contain a transmembrane domain sequence. Only 18 of the 103 clones proved to be false positive. The study demonstrates that the signal sequence trap method is an effective tool for Isolating Aplysia genes encoding secreted and membrane proteins.

EphB/ephrinB Signaling in Cell Adhesion and Migration

  • Park, Inji;Lee, Hyun-Shik
    • Molecules and Cells
    • /
    • 제38권1호
    • /
    • pp.14-19
    • /
    • 2015
  • Eph receptors and their ligands, ephrins, represent the largest group of the receptor tyrosine kinase (RTK) family, and they mediate numerous developmental processes in a variety of organisms. Ephrins are membrane-bound proteins that are mainly divided into two classes: A class ephrins, which are linked to the membrane by a glycosylphosphatidylinositol (GPI) linkage, and B class ephrins, which are transmembrane ligands. Based on their domain structures and affinities for ligand binding, the Eph receptors are also divided into two groups. Trans-dimerization of Eph receptors with their membrane-tethered ligands regulates cell-cell interactions and initiates bidirectional signaling pathways. These pathways are intimately involved in regulating cytoskeleton dynamics, cell migration, and alterations in cellular dynamics and shapes. The EphBs and ephrinBs are specifically localized and modified to promote higher-order clustering and initiate of bidirectional signaling. In this review, we present an in-depth overview of the structure, mechanisms, cell signaling, and functions of EphB/ephrinB in cell adhesion and migration.

Up-Regulation of RANK Expression via ERK1/2 by Insulin Contributes to the Enhancement of Osteoclast Differentiation

  • Oh, Ju Hee;Lee, Na Kyung
    • Molecules and Cells
    • /
    • 제40권5호
    • /
    • pp.371-377
    • /
    • 2017
  • Despite the importance of the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-RANK signaling mechanisms on osteoclast differentiation, little has been studied on how RANK expression is regulated or what regulates its expression during osteoclastogenesis. We show here that insulin signaling increases RANK expression, thus enhancing osteoclast differentiation by RANKL. Insulin stimulation induced RANK gene expression in time- and dose-dependent manners and insulin receptor shRNA completely abolished RANK expression induced by insulin in bone marrow-derived monocyte/macrophage cells (BMMs). Moreover, the addition of insulin in the presence of RANKL promoted RANK expression. The ability of insulin to regulate RANK expression depends on extracellular signal-regulated kinase 1/2 (ERK1/2) since only PD98059, an ERK1/2 inhibitor, specifically inhibited its expression by insulin. However, the RANK expression by RANKL was blocked by all three mitogen-activated protein (MAP) kinases inhibitors. The activation of RANK increased differentiation of BMMs into tartrate-resistant acid phosphatase-positive ($TRAP^+$) osteoclasts as well as the expression of dendritic cell-specific transmembrane protein (DC-STAMP) and d2 isoform of vacuolar ($H^+$) ATPase (v-ATPase) Vo domain (Atp6v0d2), genes critical for osteoclastic cell-cell fusion. Collectively, these results suggest that insulin induces RANK expression via ERK1/2, which contributes to the enhancement of osteoclast differentiation.

New Perspectives in Pediatric Nonalcoholic Fatty Liver Disease: Epidemiology, Genetics, Diagnosis, and Natural History

  • Ko, Jae Sung
    • Pediatric Gastroenterology, Hepatology & Nutrition
    • /
    • 제22권6호
    • /
    • pp.501-510
    • /
    • 2019
  • Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children. The global prevalence of pediatric NAFLD from general populations is 7.6%. In obese children, the prevalence is higher in Asia. NAFLD has a strong heritable component based on ethnic difference in the prevalence and clustering within families. Genetic polymorphisms of patatin-like phospholipase domain-containing protein 3 (PNPLA3), transmembrane 6 superfamily member 2, and glucokinase regulatory protein (GCKR) are associated with the risk of NAFLD in children. Variants of PNPLA3 and GCKR are more common in Asians. Alterations of the gut microbiome might contribute to the pathogenesis of NAFLD. High fructose intake increases the risk of NAFLD. Liver fibrosis is a poor prognostic factor for disease progression to cirrhosis. Magnetic resonance spectroscopy and magnetic resonance proton density fat fraction are more accurate for steatosis quantification than ultrasound. Noninvasive imaging methods to assess liver fibrosis, such as transient elastography, shear-wave elastography, and magnetic resonance elastography are useful in predicting advanced fibrosis, but they need further validation. Longitudinal follow-up studies into adulthood are needed to better understand the natural history of pediatric NAFLD.

RNF152 negatively regulates Wnt/β-catenin signaling in Xenopus embryos

  • Yoon, Gang-Ho;Kim, Kyuhee;Park, Dong-Seok;Choi, Sun-Cheol
    • BMB Reports
    • /
    • 제55권5호
    • /
    • pp.232-237
    • /
    • 2022
  • The Wnt/β-catenin signaling plays crucial roles in early development, tissue homeostasis, stem cells, and cancers. Here, we show that RNF152, an E3 ligase localized to lysosomes, acts as a negative regulator of the Wnt/β-catenin pathway during Xenopus early embryogenesis. Overexpression of wild-type (WT) RNF152 inhibited XWnt8-induced stabilization of β-catenin, ectopic expression of target genes, and activity of a Wnt-responsive promoter. Likewise, an E3 ligase-defective RNF152 had repressive effects on the Wnt-dependent gene responses but not its truncation mutant lacking the transmembrane domain. Conversely, knockdown of RNF152 further enhanced the transcriptional responses induced by XWnt8. RNF152 morphants exhibited defects in craniofacial structures and pigmentation. In line with this, the gain-of-RNF152 function interfered with the expression of neural crest (NC) markers, whereas its depletion up-regulated NC formation in the early embryo. Mechanistically, RNF152 inhibits the polymerization of Dishevelled, which is key to Wnt signaling, in an E3 ligase-independent manner. Together, these results suggest that RNF152 controls negatively Wnt/β-catenin signaling to fine-tune its activity for NC formation in Xenopus embryo.

Effects of Dyglomera® on leptin expression, pro-inflammatory cytokines, and adipocyte browning in 3T3-L1 cells

  • Da-Eun Min;Sung-Kwon Lee;Hae Jin Lee;Bong-Keun Choi;Dong-Ryung Lee
    • Journal of Applied Biological Chemistry
    • /
    • 제66권
    • /
    • pp.186-196
    • /
    • 2023
  • Dyglomera® is an aqueous ethanol extract derived from the fruit and pods of Dichrostachys glomerata. A previous study has revealed that Dyglomera regulates adipogenesis and lipolysis by modulating AMP-activated protein kinase (AMPK) phosphorylation and increased expression levels of lipolysis-related proteins in white adipose tissue of high fat diet-induced mice and 3T3-L1 adipocyte cells. To further investigate mechanisms of Dyglomera, additional studies were performed using 3T3-L1 cells. Results revealed that Dyglomera downregulated adipogenesis by inhibiting the protein kinase B/mammalian target of rapamycin signaling pathway and reconfirmed that it downregulated gene expression levels of proliferator-activated receptor (PPAR)-γ, CCAAT enhancer binding protein α, sterol-regulation element-binding protein-1c. Dyglomera also reduced adipokines such as tumor necrosis factor alpha, interleukin-1β, and interleukin 6 by regulating leptin expression. Moreover, Dyglomera promoted beige-and-brown adipocyte-related phenotypes and regulated metabolism by increasing mitochondrial number and expression levels of genes such as T-box protein 1, transmembrane protein 26, PR domain 16, and cluster of differentiation 40 as well as thermogenic factors such as uncoupling protein 1, proliferator-activated receptor-gamma co-activator-1α, Sirtuin 1, and PPARα through AMPK activation. Thus, Dyglomera not only can inhibit adipogenesis, but also can promote lipolysis and thermogenesis and regulate metabolism by affecting adipokine secretion from 3T3-L1 adipocytes.

VSTM2L is a promising therapeutic target and a prognostic soluble-biomarker in cholangiocarcinoma

  • Jungwhoi Lee;Woogwang Sim;Jungsul Lee;Jae-Hoon Kim
    • BMB Reports
    • /
    • 제57권7호
    • /
    • pp.324-329
    • /
    • 2024
  • The aim of the present study is to provide a rational background for silencing the V-set and transmembrane domain containing 2 like (VSTM2L) in consort with recognising soluble VSTM2L against cholangiocarcinoma. A therapeutic target against cholangiocarcinoma was selected using iterative patient partitioning (IPP) calculation, and it was verified by in vitro and in silico analyses. VSTM2L was selected as a potential therapeutic target against cholangiocarcinoma. Silencing the VSTM2L expression significantly attenuated the viability and survival of cholangiocarcinoma cells through blockade of the intracellular signalling pathway. In silico analysis showed that VSTM2L affected the positive regulation of cell growth in cholangiocarcinoma. Liptak's z value revealed that the expression of VSTM2L worsened the prognosis of cholangiocarcinoma patients. In addition, soluble VSTM2L was significantly detected in the whole blood of cholangiocarcinoma patients compared with that of healthy donors. Our report reveals that VSTM2L might be the potential therapeutic target and a soluble prognostic biomarker against cholangiocarcinoma.

Molecular Cloning and Substrate Specificity of Human NeuAc ${\alpha}$2,3Gal${\beta}$ 1,3GalNAc GalNac ${\alpha}$2,6-Sialyltransferase (hST6GalNac IV)

  • Lee, Young-Choon;Kim, Kyoung-Sook;Kim, Sang-Wan;Min, Kwan-Sik;Kim, Cheorl-Ho;Choo, Young-Kug
    • Journal of Life Science
    • /
    • 제11권1호
    • /
    • pp.57-64
    • /
    • 2001
  • The cDNA encoding human NeuAc ${\alpha}$2,3Gal$\beta$ 1,3GalNAc GalNac ${\alpha}$2,6-Sialyltransferase (hST6GalNac IV) was isolated by screening of human fetal liver cDNA library with a DNA probe generated from the cDNA sequence of mouse ST6Gal NAc IV (mkST6GalNAc IV). The cDNA sequence included an open reading frame coding for 302 amino acids, and comparative analysis of this cDNA with mST6GalNAc IV showed that each sequence of the predicted coding region contains 88% and 85% identifies in nucleotide and amino acid levels, respecively. The primary structure of this enzyme suggested a putative domain structure, like that in other glycosyltransferases, consisting of a short N-terminal cytoplamic domain, a transmembrane domain and a large C-terminal active domain. This enzyme expressed in COS-7 cells echibited transferase activity toward NeuAc ${\alpha}$2,3Gal$\beta$ 1,3GalNAc, fetuin and GM1b, although the activity toward the later is very low, no significant activity being detected toward Gal${\beta}$ 1,3Gal NAc or asialofetuin, the other glycoprotein substrates tested. The $^{14}$ C-sialylated residue of fetuin sialylated by this enzyem with CMP-[$^{14}$C]NeuAc was sensitive to treatment with ${\alpha}$2,8-specific sialidase of Vibrio cholerae but resistant to treatment with ${\alpha}$2,3-specific sialidase (NaNase I), and ${\alpha}$2,3- and ${\alpha}$2,8-specific sialidase of Newcastle disease virus. These results clearly indicated that the expressed enzyme is a type of GalNAc ${\alpha}$2,6-sialyltransferase like mST6GalNAc IV, which requires sialic acid residues linked to Gal${\beta}$1,3GalNAc-residues for its activity.

  • PDF