• Title/Summary/Keyword: protein function analysis

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Identification of Mutations in Protein Kinase CKIIβ Subunit That Affect Its Binding to Ribosomal Protein L41 and Homodimerization

  • Ahn, Bong-Hyun;Lee, Ji-Hoon;Bae, Young-Seuk
    • BMB Reports
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    • v.36 no.4
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    • pp.344-348
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    • 2003
  • Protein kinase CKII is composed of two catalytic ($\alpha$ or $\alpha$') subunits and two regulatory ($\beta$) subunits. The $CKII{\beta}$ subunit is thought to mediate the tetramer formation and interact with other target proteins. However, its physiological function remains obscure. In this study, point mutants of $CKII{\beta}$ that are defective for the L41 binding were isolated by using the reverse two-hybrid system. A sequence analysis of the point mutants revealed that Asp-26, Met-52, and Met-78 of $CKII{\beta}$ are critical for L41 binding; Asn-67 (and/or Lys-139) and Met-52 are important for $CKII{\beta}$ homodimerization. Two point mutants, R75 and R83, of $CKII{\beta}$ interacted with L5, topoisomerase $II{\beta}$, and CKBBP1/SAG, but not with the wild-type $CKII{\beta}$. This indicates that $CKII{\beta}$ homodimerization is not a prerequisite for its binding to target proteins. These $CKII{\beta}$ point mutants may be useful in exploring the biochemical physiological functions of $CKII{\beta}$.

Isolation and Partial Characterization of Hemin-binding Cell Envelope Proteins from Porphyromonas gingivalis, Prevotella intermedia, and Prevotella nigrescens (Porphyromonas gingivalis, Prevotella intermedia, 그리고 Prevotella nigrescens에서의 hemin 결합 단백질에 대한 연구)

  • Kim, Sung-Jo
    • Journal of Periodontal and Implant Science
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    • v.36 no.1
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    • pp.155-165
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    • 2006
  • The results of this study confirm that the availability of hemin influences the expression of selected membrane proteins of Porphyromonas gingivalis, Prevotella intermedia, and Prevotella nigrescens. A 30 kDa (heated 24 kDa) hemin-binding protein whose expression is hemin regulated was identified and purified in P. gingivalis. A strong hemin-binding function was found by LDS-PAGE and TMBZ staining when P. gingivalis cells were grown under hemin-limited conditions. A 50 kDa cell envelope associated protein, whose expression is hemin regulated, is considered to be a putative hemin binding protein from P. intermedia and P. nigrescens, respectively. N-terminal amino acid sequence analysis of CNBr-digested 24 kDa hemin binding protein from P. gingivalis revealed that this protein belongs to a new, so far undescribed hemin-binding class of proteins. N-terminal amino acid sequence of a 50 kDa putative hemin binding protein from P. intermedia was identical with Enolase from Streptococcus intermedia. Work is in progress to further characterize the molecular structure of these proteins.

Analysis of the Biological Function of ELDF15 Using an Antisense Recombinant Expression Vector

  • Liu, Yan;Wang, Long;Wang, Zi-Jun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9131-9136
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    • 2014
  • ELDF15, homologous with AT2 receptor-interaction protein 1 (ATIP1), may play an important role in cell differentiation, proliferation, and carcinogenesis. We aimed to understand the biological function of ELDF15 via construction and transfection of a recombinant expression vector containing antisense ELDF15. Recombinant expression vectors were successfully constructed and transfected into K562 cells. A stable transfectant, known as pXJ41-asELDF15, stably produced antisense ELDF15. Compared with K562 and K562-zeo cells, K562-pXJ41-asELDF15 cells showed inhibition of cell proliferation. RT-PCR analysis showed that the expression and protein level of ELDF15 decreased significantly in K562 cells transfected with pXJ41-asELDF15. Expression of hemoglobin increased in K562 cells transfected with pXJ41-asELDF15 by benzidine staining. increases NBT reduction activity in K562 cells transfected with pXJ41-asELDF15.Colony forming efficiency in two-layer soft agar was clearly inhibited as assessed by electron microscopy. These results suggest that ELDF15 plays a potential role in cell differentiation, proliferation and carcinogenesis.

Transcriptional Profiling and Dynamical Regulation Analysis Identify Potential Kernel Target Genes of SCYL1-BP1 in HEK293T Cells

  • Wang, Yang;Chen, Xiaomei;Chen, Xiaojing;Chen, Qilong;Huo, Keke
    • Molecules and Cells
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    • v.37 no.9
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    • pp.691-698
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    • 2014
  • SCYL1-BP1 is thought to function in the p53 pathway through Mdm2 and hPirh2, and mutations in SCYL1-BP1 are associated with premature aging syndromes such as Geroderma Osteodysplasticum; however, these mechanisms are unclear. Here, we report significant alterations in miRNA expression levels when SCYL1-BP1 expression was inhibited by RNA interference in HEK293T cells. We functionally characterized the effects of potential kernel miRNA-target genes by miRNA-target network and protein-protein interaction network analysis. Importantly, we showed the diminished SCYL1-BP1 dramatically reduced the expression levels of EEA1, BMPR2 and BRCA2 in HEK293T cells. Thus, we infer that SCYL1-BP1 plays a critical function in HEK293T cell development and directly regulates miRNA-target genes, including, but not limited to, EEA1, BMPR2, and BRCA2, suggesting a new strategy for investigating the molecular mechanism of SCYL1-BP1.

Reduction of Muscarinic $K^+$ Channel Activity by Transferrin in Ischemic Rat Atrial Myocytes

  • Park, Kyeong-Tae;Kang, Da-Won;Han, Jae-Hee;Hur, Chang-Gi;Hong, Seong-Geun
    • The Korean Journal of Physiology and Pharmacology
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    • v.7 no.6
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    • pp.333-339
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    • 2003
  • It has been demonstrated that an unidentified cytosolic factor(s) reduces $K_{ACh}$ channel function. Therefore, this study attempted to elucidate the cytosolic factor. Fresh cytosol isolated from normal heart (FC) depressed the $K_{ACh}$ channel activity, but cytosol isolated from the ischemic hearts (IC) did not modulate the channel function. Electrophorectic analysis revealed that a protein of ${\sim}80 kDa was markedly reduced or even lost in IC. By using peptide sequencing analysis and Western blot, this 80 kDa protein was identified as transferrin (receptor-mediated $Fe^{3+}$ transporter, 76 kDa). Direct application of transferrin (100 nM) to the cytoplasmic side of inside-out patches decreased the open probability ($P_o$, 12.7${\pm}6.4%, n=4) without change in mean open time (${\tau}_o$, $98.5{\pm}1.3$%, n=4). However, the equimolar apotransferrin, which is free of $Fe^{3+}$, had no effect on the channel activity (N*$P_o$, $129.1{\pm}13.5$%, n=3). Directly applied $Fe^{3+}$ (100 nM) showed results similar to those of transferrin (N*$P_o$: $21.1{\pm}3.9$%, n=5). However $Fe^{2+}$ failed to reduce the channel function (N*$P_o$, $106.3{\pm}26.8$%, n=5). Interestingly, trivalent cation La3+ inhibited N*$P_o$ of the channel ($6.1{\pm}3.0$%, n=3). Taken together, these results suggest that $Fe^{3+}$ bound to transferrin can modulate the $K_{ACh}$ channel function by its electrical property as a polyvalent cation.

Analysis of TIMP-2 and Vimentin Protein Expression and Epigenetic Reprogramming in Cloned Bovine Placentae

  • Kim, Hong-Rye;Han, Rong-Xun;Lee, Hye-Ran;Yoon, Jong-Taek;Cheong, Hee-Tae;Park, Chang-Sik;Jin, Dong-Il
    • Reproductive and Developmental Biology
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    • v.31 no.2
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    • pp.97-102
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    • 2007
  • The objective of this study was to analyzed pattern of proteins expression abnormally in cloned bovine placenta. TIMP-2 protein whose function is related to extracellular matrix degradation and tissue remodeling processes was one of differentially up-regulated proteins in SCNT placenta. And one of down-regulated protein in SCNT placenta was identified as vimentin protein that is presumed to stabilize the architecture of the cytoplasm. The expression patterns of these proteins were validated by Western blotting. To evaluate how regulatory loci. of TIMP-2 and vimentin genes was programmed reprogramming in cloned placenta. the status of DNA methylation in the promoter region of TIMP-2 and vimentin genes was analyzed by sodium Bisulfite mapping. The DNA methylation results showed that there was not difference in methylation pattern of TIMP-2 and vimentin loci between cloned and normal placenta. Histone H3 acetylation state of the nucleosome was analyzed in the cloned placental and normal placenta by Western blotting. A small portion of the protein lysates were subjected to Western blotting with the antibodies against anti acetyl-Histone H3. Overall histone H3 acetylation state of SCNT placenta was significantly higher than those of normal placenta cells. It is postulated that cloned placenta at the end of gestation seems to be unusual in function and morphology of placenta via improper expression of TIMP-2 and vimentin by abnormal acetylation states of cloned genome.

Analysis of Clinical Biochemical Components in Sera of Tsutsugamushi Disease Patients

  • Kim, Chong-Ho;Park, Seung-Taeck;Oh, Geum-Ga
    • Biomedical Science Letters
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    • v.13 no.4
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    • pp.287-291
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    • 2007
  • The factors and mechanisms by infection of Oriental Tsutsugamushi caused disease are not well understood. The onset of tsutsugamushi disease is characterized by chilliness, fever, malaise, headache and generalized aching. Infection of tsutsugamushi is the cause of impairment of function of a major organ often complicate the picture and immediately change the prognosis for the worse. Tsutsugamushi disease is reported that this disease is characterized by the histopathogenesis of liver, kidney, heart, and lung, but the variation of biochemical components in serum of tsutsugamushi disease patient are not clear. We analyzed total protein (TP), albumin (AL), aspartic aminotranferase (AST), alanine aminotransferase (ALT), alkaline phosphotase (ALP), urea nitrogen (UN), creatinine (CRE), glucose (GLD), cholesterol (CHOL) and total bilirubin (TB) in sera of patients with tsutsugamushi disease. In comparison with reference, total protein and albumin were abnormally decreased in 19.6% and 39.2% of patients, respectively. AST, ALT, ALP, creatinine, UN, glucose, cholesterol and total bilirubin were abnormally increased in 94.1 %, 72.5%, 25.5%, 15.7%, 9.8%, 62.7%, 25.5% and 6.0% of patients, respectively. The patients showed abnormal relative rate of protein electrophoretic fractions to total protein in serum compared to them of reference were 43.1% (albumin), 12.9% ($\alpha_1$-globulin), 58.8% ($\alpha_2$-globulin), 60.8% ($\beta$-globulin) and 70.6% ($\gamma$-globulin), respectively. These data suggest that infection of Oriental Tsutsugamushi causes impairment of function of a major organ and abnormal serum protein electrophoresis fractions to tsutsugamushi patients.

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Cloning and Expression Analysis of Gonadogenesis-associated Gene SPATA4 from Rainbow Trout (Oncorhynchus mykiss)

  • Liu, Bowen;Liu, Shangfeng;He, Shan;Zhao, Ying;Hu, Hongxia;Wang, Zhao
    • BMB Reports
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    • v.38 no.2
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    • pp.206-210
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    • 2005
  • Gonadogenesis is a complicated process which involves multi-gene interactions. A rainbow trout (Oncorhynchus mykiss) gene spermatogenesis associated 4 (SPATA4) was cloned and characterized from adult rainbow trout testis. The cDNA sequence of rainbow trout SPATA4 contains an open reading frame of 1, 081 nucleatides encoding a putative protein of 259 amino acids. The putative protein from rainbow trout shares a 76.8% homology with zebrafish SPATA4. No trans-membrane regions or signal peptide were detected using bioinformatics methods. Subcellular localization analysis revealed that rainbow trout SPATA4 was a nuclear protein with highest possibility (39.1%). Multi-tissue reverse transcriptase PCR (RT-PCR) was performed to examine the distribution of rainbow trout SPATA4 in eleven organs of adult rainbow trout. The result demonstrated that this gene express specifically in testis and slight amount of expression was detected in ovary. Further analysis of SPATA4 characterization and function in rainbow trout may provide insight into the understanding of gonadogenesis process.

Lycopersicon Eculentum C2H2-type Zinc Finger Protein Induced by Oxidative Stress Especially

  • Seong, Eun-Soo;Lee, Ji-Yeon;Yu, Chang-Yeon;Yang, Deok-Chun;Eom, Seok-Hyun;Cho, Dong-Ha
    • Journal of Plant Biotechnology
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    • v.34 no.3
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    • pp.167-172
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    • 2007
  • A tomato zinc-finger protein gene, LeZFP1, encoding the Cys2/His2-type zinc-finger transcription factor was searched from cDNA microarray analysis of gene expression following induction of the overexpressed tomato transgenic plants showing resistance for pathogen and abiotic stresses. The full-length cDNA of LeZFP1 encoded a protein of 261 amino acid residues. Analysis of the deduced amino acid sequence of LeZFP1 revealed that it shares high sequence identity with pepper CAZFP1 (81% identity). We found that single copy of LeZFP1 gene is present in the tomato genome through southern blot analysis. The LeZFP1 transcripts were constitutively expressed in the tomato mature and young leaves, but were detectable weakly in the flower, stem and root. The LeZFP1 transcripts were significantly reduced in treated leaf tissues with NaCl and mannitol. The LeZFP1 gene was induced by oxidative stress especially. Our results indicated that LeZFP1 may play a role function involved in oxidative stress signaling pathways.

Detection of Matrix Metalloprotease-9 and Analysis of Protein Patterns in Bovine Vaginal Mucus during Estrus and Pregnancy

  • Kim, Sang-Hwan;Baek, Jun-Seok;Lee, Ho-Jun;Min, Kwan-Sik;Lee, Deuk-Hwan;Yoon, Jong-Taek
    • Journal of Embryo Transfer
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    • v.27 no.2
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    • pp.93-100
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    • 2012
  • To investigate the biochemical nature of changes in vaginal physiology during estrus and pregnancy, we examined the cytology and viscosity, and monitored the protein expression profile in vaginal mucus during estrus and pregnancy. The viscosity progressively decreased from estrus to pregnancy. Cell type analysis revealed that white blood cells progressively increased from estrus to pregnancy, while red blood cells progressively decreased during pregnancy. The cornification index (CI) was higher in estrus than in pregnancy. Protein mass spectrumetry identified the presence of ribosome-binding protein 1, GRIP 1 (Glutamate receptor-interacting protein 1)-associated protein 1, DUF729 (Domain of unknown function729) domain-containing protein 1, prolactin precursor, dihydrofolatereductase, and MMP (Matrix metalloprotease)-9 in vaginal mucus. MMP-2 and MMP-9 proteins in the vaginal mucus were active throughout estrus and gestation, as measured by a gelatinase assay, but most abundant in the vaginal mucus on day 0 of estrus. Results from ELISA of MMP-2 and MMP-9 were in accordance with the gelatinase assay. In light of the crucial role of metalloproteinases in extracellular matrix remodeling, the level of MMP-9 in vaginal mucus might be useful as an indicator of estrus and pregnancy to increase the efficiency of reproduction.