scholarly journals TWISTED DWARF1, a Unique Plasma Membrane-anchored Immunophilin-like Protein, Interacts with Arabidopsis Multidrug Resistance-like Transporters AtPGP1 and AtPGP19

2003 ◽  
Vol 14 (10) ◽  
pp. 4238-4249 ◽  
Author(s):  
Markus Geisler ◽  
H. Üner Kolukisaoglu ◽  
Rodolphe Bouchard ◽  
Karla Billion ◽  
Joachim Berger ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Protein Interaction ◽  
Single Gene ◽  
Integral Membrane Protein ◽  
Prolyl Isomerase ◽  
Ppiase Activity ◽  
Peptidyl Prolyl Isomerase ◽  
Protein Protein Interaction ◽  
Cdna Sequences

Null-mutations of the Arabidopsis FKBP-like immunophilin TWISTED DWARF1 (TWD1) gene cause a pleiotropic phenotype characterized by reduction of cell elongation and disorientated growth of all plant organs. Heterologously expressed TWD1 does not exhibit cis-trans-peptidylprolyl isomerase (PPIase) activity and does not complement yeast FKBP12 mutants, suggesting that TWD1 acts indirectly via protein-protein interaction. Yeast two-hybrid protein interaction screens with TWD1 identified cDNA sequences that encode the C-terminal domain of Arabidopsis multidrugresistance-like ABC transporter AtPGP1. This interaction was verified in vitro. Mapping of protein interaction domains shows that AtPGP1 surprisingly binds to the N-terminus of TWD1 harboring the cis-trans peptidyl-prolyl isomerase-like domain and not to the tetratrico-peptide repeat domain, which has been shown to mediate protein-protein interaction. Unlike all other FKBPs, TWD1 is shown to be an integral membrane protein that colocalizes with its interacting partner AtPGP1 on the plasma membrane. TWD1 also interacts with AtPGP19 (AtMDR1), the closest homologue of AtPGP1. The single gene mutation twd1-1 and double atpgp1-1/atpgp19-1 (atmdr1-1) mutants exhibit similar phenotypes including epinastic growth, reduced inflorescence size, and reduced polar auxin transport, suggesting that a functional TWD1-AtPGP1/AtPGP19 complex is required for proper plant development.

scholarly journals The Peptidyl-Prolyl Isomerase Activity of SlyD Is Not Required for Maturation of Escherichia coli Hydrogenase

2007 ◽  
Vol 189 (21) ◽  
pp. 7942-7944 ◽  
Author(s):  
Jie Wei Zhang ◽  
Michael R. Leach ◽  
Deborah B. Zamble
Keyword(s):  
Escherichia Coli ◽  
Metal Cluster ◽  
The Other ◽  
Prolyl Isomerase ◽  
Ppiase Activity ◽  
Peptidyl Prolyl Isomerase ◽  
Isomerase Activity ◽  
Hydrogenase Enzymes

ABSTRACT Escherichia coli SlyD, which is involved in the biosynthesis of the metal cluster in the [NiFe]-hydrogenase enzymes, exhibits several activities including that of a peptidyl-prolyl isomerase (PPIase). Mutations that result in deficient PPIase activity do not produce corresponding decreases in the other activities of SlyD in vitro or in hydrogenase production levels in vivo.

Effect of FKBP65, a putative elastin chaperone, on the coacervation of tropoelastin in vitro

2010 ◽  
Vol 88 (6) ◽  
pp. 917-925 ◽  
Author(s):  
Kevin L.Y. Cheung ◽  
Matthew Bates ◽  
Vettai S. Ananthanarayanan
Keyword(s):  
Self Assembly ◽  
Secretory Pathway ◽  
Molar Ratio ◽  
Prolyl Isomerase ◽  
Ppiase Activity ◽  
Peptidyl Prolyl Isomerase ◽  
Maturation Stages ◽  
Turbidimetric Assay

FKBP65 is a protein of the endoplasmic reticulum that is relatively abundant in elastin-producing cells and is associated with tropoelastin in the secretory pathway. To test an earlier suggestion by Davis and co-workers that FKBP65 could act as an intracellular chaperone for elastin, we obtained recombinant FKBP65 (rFKBP65) by expressing it in E. coli and examined its effect on the coacervation characteristics of chicken aorta tropoelastin (TE) using an in vitro turbidimetric assay. Our results reveal that rFKBP65 markedly promotes the initiation of coacervation of TE without significantly affecting the temperature of onset of coacervation. This effect shows saturation at a 1:2 molar ratio of TE to rFKBP65. By contrast, FKBP12, a peptidyl prolyl isomerase, has a negligible effect on TE coacervation. Moreover, the effect of rFKBP65 on TE coacervation is unaffected by the addition of rapamycin, an inhibitor of peptidyl prolyl isomerase (PPIase) activity. These observations rule out the involvement of the PPIase activity of rFKBP65 in modulating the coacervation of TE. Additional experiments using a polypeptide model of TE showed that rFKBP65, while promoting coacervation, may retard the maturation of this model polypeptide into larger aggregates. Based on these results, we suggest that FKBP65 may act as an elastin chaperone in vivo by controlling both the coacervation and the maturation stages of its self-assembly into fibrils.

scholarly journals Interaction of the transmembrane domain of lysis protein E from bacteriophage ϕX174 with bacterial translocase MraY and peptidyl-prolyl isomerase SlyD

Microbiology ◽  
2006 ◽  
Vol 152 (10) ◽  
pp. 2959-2967 ◽  
Author(s):  
Sharon Mendel ◽  
Joanne M. Holbourn ◽  
James A. Schouten ◽  
Timothy D. H. Bugg
Keyword(s):  
Transmembrane Domain ◽  
Integral Membrane Protein ◽  
Cd Spectroscopy ◽  
Prolyl Isomerase ◽  
Peptidyl Prolyl Isomerase ◽  
E Coli ◽  
Protein Protein Interaction ◽  
Peptidoglycan Biosynthesis ◽  
Membrane Bound ◽  
A Site

The molecular target for the bacteriolytic E protein from bacteriophage ϕX174, responsible for host cell lysis, is known to be the enzyme phospho-MurNAc-pentapeptide translocase (MraY), an integral membrane protein involved in bacterial cell wall peptidoglycan biosynthesis, with an essential role being played by peptidyl-prolyl isomerase SlyD. A synthetic 37 aa peptide Epep, containing the N-terminal transmembrane α-helix of E, was found to be bacteriolytic against Bacillus licheniformis, and inhibited membrane-bound MraY. The solution conformation of Epep was found by circular dichroism (CD) spectroscopy to be 100 % α-helical. No change in the CD spectrum was observed upon addition of purified Escherichia coli SlyD, implying that SlyD does not catalyse prolyl isomerization upon E. However, Epep was found to be a potent inhibitor of SlyD-catalysed peptidyl-prolyl isomerization (IC50 0.15 μM), implying a strong interaction between E and SlyD. Epep was found to inhibit E. coli MraY activity when assayed in membranes (IC50 0.8 μM); however, no inhibition of solubilized MraY was observed, unlike nucleoside natural product inhibitor tunicamycin. These results imply that the interaction of E with MraY is not at the MraY active site, and suggest that a protein–protein interaction is formed between E and MraY at a site within the transmembrane region.

scholarly journals Definition of a minimal munc18c domain that interacts with syntaxin 4

2000 ◽  
Vol 350 (3) ◽  
pp. 741-746 ◽  
Author(s):  
Julian GRUSOVIN ◽  
Violet STOICHEVSKA ◽  
Keith H. GOUGH ◽  
Katrina NUNAN ◽  
Colin W. WARD ◽  
...  
Keyword(s):  
Protein Interaction ◽  
Full Length ◽  
Yeast Two Hybrid ◽  
Protein Protein Interaction ◽  
Interaction Studies ◽  
Syntaxin 4 ◽  
Definition Of ◽  
Two Hybrid

munc18c is a critical protein involved in trafficking events associated with syntaxin 4 and which also mediates inhibitory effects on vesicle docking and/or fusion. To investigate the domains of munc18c responsible for its interaction with syntaxin 4, fragments of munc18c were generated and their interaction with syntaxin 4 examined in vivo by the yeast two-hybrid assay. In vitro protein–protein interaction studies were then used to confirm that the interaction between the proteins was direct. Full-length munc18c1–592, munc18c1–139 and munc18c1–225, but not munc18c226–592, munc18c1–100, munc18c43–139 or munc18c66–139, interacted with the cytoplasmic portion of syntaxin 4, Stx42–273, as assessed by yeast two-hybrid assay of growth on nutritionally deficient media and by β-galactosidase reporter induction. The N-terminal predicted helix-a-helix-b-helix-c region of syntaxin 4, Stx429–157, failed to interact with full-length munc18c1–592, indicating that a larger portion of syntaxin 4 is necessary for the interaction. The yeast two-hybrid results were confirmed by protein–protein interaction studies between Stx42–273 and glutathione S-transferase fusion proteins of munc18c. Full-length munc18c1–592, munc18c1–139 and munc18c1–225 interacted with Stx42–273 whereas munc18c1–100 did not, consistent with the yeast two-hybrid data. These data thus identify a region of munc18c between residues 1 and 139 as a minimal domain for its interaction with syntaxin 4.

scholarly journals FK506-binding protein FklB is involved in biofilm formation through its peptidyl-prolyl isomerase activity

2020 ◽  
Author(s):  
Chrysoula Zografou ◽  
Maria Dimou ◽  
Panagiotis Katinakis
Keyword(s):  
Biofilm Formation ◽  
Negative Regulator ◽  
Cell Length ◽  
Wild Type ◽  
Prolyl Isomerase ◽  
Ppiase Activity ◽  
Peptidyl Prolyl Isomerase ◽  
Knock Out ◽  
E Coli ◽  
The Mean

AbstractFklB is a member of the FK506-binding proteins (FKBPs), a family that consists of five genes in Escherichia coli. Little is known about the physiological and functional role of FklB in bacterial movement. In the present study, FklB knock-out mutant ΔfklB presented an increased swarming and swimming motility and biofilm formation phenotype, suggesting that FklB is a negative regulator of these cellular processes. Complementation with Peptidyl-prolyl isomerase (PPIase)-deficient fklB gene (Y181A) revealed that the defects in biofilm formation were not restored by Y181A, indicating that PPIase activity of FklB is modulating biofilm formation in E. coli. The mean cell length of ΔfklB swarming cells was significantly smaller as compared to the wild-type BW25113. Furthermore, the mean cell length of swarming and swimming wild-type and ΔfklB cells overexpressing fklB or Y181A was considerably larger, suggesting that PPIase activity of FklB plays a role in cell elongation and/or cell division. A multi-copy suppression assay demonstrated that defects in motility and biofilm phenotype were compensated by overexpressing sets of PPIase-encoding genes. Taken together, our data represent the first report demonstrating the involvement of FklB in cellular functions of E. coli.

scholarly journals Cdk2 and Pin1 negatively regulate the transcriptional corepressor SMRT

2008 ◽  
Vol 183 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Kristopher J. Stanya ◽  
Yu Liu ◽  
Anthony R. Means ◽  
Hung-Ying Kao
Keyword(s):  
Transcriptional Repression ◽  
Mammalian Cells ◽  
Cellular Response ◽  
Thyroid Hormone Receptor ◽  
Signaling Cascade ◽  
Phosphorylation Sites ◽  
Transcriptional Corepressor ◽  
Prolyl Isomerase ◽  
Peptidyl Prolyl Isomerase

Silencing mediator for retinoic acid and thyroid hormone receptor (SMRT) is a transcriptional corepressor that participates in diverse signaling pathways and human diseases. However, regulation of SMRT stability remains largely unexplored. We show that the peptidyl-prolyl isomerase Pin1 interacts with SMRT both in vitro and in mammalian cells. This interaction requires the WW domain of Pin1 and SMRT phosphorylation. Pin1 regulates SMRT protein stability, thereby affecting SMRT-dependent transcriptional repression. SMRT phosphorylation at multiple sites is required for Pin1 interaction, and these sites can be phosphorylated by Cdk2, which interacts with SMRT. Cdk2-mediated phosphorylation of SMRT is required for Pin1 binding and decreases SMRT stability, whereas mutation of these phosphorylation sites abrogates Pin1 binding and stabilizes SMRT. Finally, decreases in SMRT stability occur in response to the activation of Her2/Neu/ErbB2, and this receptor functions upstream of both Pin1 and Cdk2 in the signaling cascade that regulates SMRT stability and cellular response to tamoxifen.

scholarly journals Methods for addressing the protein-protein interaction between histone deacetylase 6 and ubiquitin

2017 ◽  
Author(s):  
Carolina dos S. Passos ◽  
Nathalie Deschamps ◽  
Yun Choi ◽  
Robert E. Cohen ◽  
Remo Perozzo ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Stress Response ◽  
Small Molecules ◽  
Histone Deacetylase ◽  
Protein Interaction ◽  
Potential Role ◽  
Histone Deacetylase 6 ◽  
Protein Protein Interaction ◽  
Binding Function

AbstractHistone deacetylase 6 (HDAC6) is a cytoplasmic HDAC isoform able to remove acetyl groups from cellular substrates such as α-tubulin. In addition to the two deacetylase domains, HDAC6 has a C-terminal zinc-finger ubiquitin (Ub)-binding domain (ZnF-UBP) able to recognize free Ub. HDAC6-Ub interaction is thought to function in regulating the elimination of misfolded proteins during stress response through the aggresome pathway. Small molecules inhibiting deacetylation by HDAC6 were shown to reduce aggresomes, but the interplay between HDAC6 catalytic activity and Ub-binding function is not fully understood. Here we describe two methods to measure the HDAC6-Ub interaction in vitro using full-length HDAC6. Both methods were effective for screening inhibitors of the HDAC6-Ub protein-protein interaction independently of the catalytic activity. Our results suggest a potential role for the HDAC6 deacetylase domains in modulating HDAC6-Ub interaction. This new aspect of HDAC6 regulation can be targeted to address the roles of HDAC6-Ub interaction in normal and disease conditions.

Specificity of protein-RNA and protein-protein interaction upon assembly of TMV in vivo and in vitro

Virology ◽  
1975 ◽  
Vol 67 (1) ◽  
pp. 1-13 ◽  
Author(s):  
T.I. Atabekova ◽  
M.E. Taliansky ◽  
J.G. Atabekov
Keyword(s):  
Protein Interaction ◽  
Protein Protein Interaction
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