scholarly journals Design and validation of plasmid vectors for characterizing protein-protein interactions in Spodoptera frugiperda insect cells

2021 ◽  
Author(s):  
Hao Wei Teh ◽  
Kathleen Martin ◽  
Anna E Whitfield
Keyword(s):  
Protein Interactions ◽  
Insect Cells ◽  
Insect Vector ◽  
Terminal Portion ◽  
Protein Protein Interactions ◽  
Flag Epitope ◽  
Epitope Tag ◽  
Plasmid Vectors ◽  
Amino Terminal ◽  
Molecular Fluorescence

There are limited molecular biology resources for interrogating protein-protein interactions (PPI) in insect cells. To address this deficiency, we developed plasmid vectors for localization, bi-molecular fluorescence complementation (BiFC), and co-immunoprecipitation (co-IP) assays in Sf9 insect cells. Plasmids were designed to express a protein of interest as a fusion with epitope tags and autofluorescent proteins using the Gateway cloning system. Two robust interactors were utilized to validate this system, the nucleoprotein (N) and the phosphoprotein (P) of maize mosaic virus. The viral N was fused with the carboxy-terminal portion of eYFP and a FLAG epitope tag, and P was fused with the amino-terminal portion of eYFP and a c-myc epitope tag. The two expression plasmids were co-transfected into Sf9 cells, and fluorescence microscopy was used to visualize BiFC and co-IP was performed to confirm that this system was sensitive enough to detect PPI between the two proteins. BiFC was seen in cells co-transfected with N and P and co-IP validated the interaction. This plasmid-based system can be used to investigate a variety of PPI that occur in insects. We validated viral protein interactions that occur in the insect vector which provides further insights into the biology of rhabdoviruses that are transmitted by insects. The ability to express viral and insect proteins in insect cells for studying PPI with this streamlined system represents an advancement for protein research in insects. Future work will focus on identifying interacting viral and host proteins and discovery of targets for control of viruses and insect vectors.

scholarly journals Interactions between Integrase and Excisionase in the Phage Lambda Excisive Nucleoprotein Complex

2002 ◽  
Vol 184 (18) ◽  
pp. 5200-5203 ◽  
Author(s):  
Eun Hee Cho ◽  
Richard I. Gumport ◽  
Jeffrey F. Gardner
Keyword(s):  
Protein Interactions ◽  
Protein Protein Interactions ◽  
Mobility Shift ◽  
Host Chromosome ◽  
Amino Terminal ◽  
Nucleoprotein Complex ◽  
Carboxyl Terminal ◽  
Α Helix ◽  
Gel Mobility Shift ◽  
Amino Terminal Domain

ABSTRACT Bacteriophage lambda site-specific recombination comprises two overall reactions, integration into and excision from the host chromosome. Lambda integrase (Int) carries out both reactions. During excision, excisionase (Xis) helps Int to bind DNA and introduces a bend in the DNA that facilitates formation of the proper excisive nucleoprotein complex. The carboxyl-terminal α-helix of Xis is thought to interact with Int through direct protein-protein interactions. In this study, we used gel mobility shift assays to show that the amino-terminal domain of Int maintained cooperative interactions with Xis. This finding indicates that the amino-terminal arm-type DNA binding domain of Int interacts with Xis.

Cardiac hypertrophy and altered β-adrenergic signaling in transgenic mice that express the amino terminus of β-ARK1

2003 ◽  
Vol 285 (5) ◽  
pp. H2201-H2211 ◽  
Author(s):  
Janelle R. Keys ◽  
Emily A. Greene ◽  
Chris J. Cooper ◽  
Sathyamangla V. Naga Prasad ◽  
Howard A. Rockman ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Cardiac Hypertrophy ◽  
Protein Interactions ◽  
Amino Terminus ◽  
Amino Acid Residues ◽  
Protein Protein Interactions ◽  
Gpcr Signaling ◽  
Amino Terminal ◽  
G Protein Coupled

The G protein-coupled receptor (GPCR) kinase β-adrenergic receptor (β-AR) kinase-1 (β-ARK1) is elevated during heart failure; however, its role is not fully understood. β-ARK1 contains several domains that are capable of protein-protein interactions that may play critical roles in the regulation of GPCR signaling. In this study, we developed a novel line of transgenic mice that express an amino-terminal peptide of β-ARK1 that is comprised of amino acid residues 50–145 (β-ARKnt) in the heart to determine whether this domain has any functional significance in vivo. Surprisingly, the β-ARKnt transgenic mice presented with cardiac hypertrophy. Our data suggest that the phenotype was driven via an enhanced β-AR system, as β-ARKnt mice had elevated cardiac β-AR density. Moreover, administration of a β-AR antagonist reversed hypertrophy in these mice. Interestingly, signaling through the β-AR in response to agonist stimulation was not enhanced in these mice. Thus the amino terminus of β-ARK1 appears to be critical for normal β-AR regulation in vivo, which further supports the hypothesis that β-ARK1 plays a key role in normal and compromised cardiac GPCR signaling.

scholarly journals Domain swapping reveals the modular nature of Fos, Jun, and CREB proteins.

1990 ◽  
Vol 10 (9) ◽  
pp. 4565-4573 ◽  
Author(s):  
L J Ransone ◽  
P Wamsley ◽  
K L Morley ◽  
I M Verma
Keyword(s):  
Dna Binding ◽  
Protein Interactions ◽  
Leucine Zipper ◽  
Chimeric Protein ◽  
Domain Swapping ◽  
Amino Terminus ◽  
Protein Protein Interactions ◽  
Amino Terminal ◽  
Nih 3T3 ◽  
Basic Region

The products of the Jun and Fos proto-oncogenes form a heterodimer that binds to and activates transcription from 12-O-tetradecanoylphorbol-13-acetate-responsive promoter elements (TGACTCA) and AP-1-binding sites (TGACATCA). These two proteins belong to a family of related transcription factors which contain similar domains required for protein dimerization and DNA binding but display different protein and DNA binding specificities. The basic region, required for DNA binding, is followed by a leucine zipper structure, a domain that mediates protein-protein interactions. To assess the role of these two domains in three related proteins, Fos, Jun, and CREB, we carried out extensive domain-swapping analysis. We found that (i) dimers formed by two Jun leucine zipper-containing proteins were unable to bind DNA as efficiently as a Fos-Jun combination, regardless of the source of the basic region; (ii) the Fos leucine zipper was unable to form either homo- or heterodimers with a chimeric protein containing a Fos leucine zipper; (iii) the Fos basic region was capable of binding to an AP-1 site; (iv) replacement of the Jun amino terminus with that of CREB had little effect on dimerization, whereas replacement with the amino terminus of Fos disrupted both protein-protein and protein-DNA interactions; (v) changes in relative affinities of the Fos and Jun basic regions for the AP-1 element were dependent on the secondary contributions of amino-terminal residues; and (vi) the Fos-Jun chimeric constructs cooperated in transcriptional transactivation of the Jun promoter in NIH 3T3 cells.

Domain swapping reveals the modular nature of Fos, Jun, and CREB proteins

1990 ◽  
Vol 10 (9) ◽  
pp. 4565-4573
Author(s):  
L J Ransone ◽  
P Wamsley ◽  
K L Morley ◽  
I M Verma
Keyword(s):  
Dna Binding ◽  
Protein Interactions ◽  
Leucine Zipper ◽  
Chimeric Protein ◽  
Domain Swapping ◽  
Amino Terminus ◽  
Protein Protein Interactions ◽  
Amino Terminal ◽  
Nih 3T3 ◽  
Basic Region

The products of the Jun and Fos proto-oncogenes form a heterodimer that binds to and activates transcription from 12-O-tetradecanoylphorbol-13-acetate-responsive promoter elements (TGACTCA) and AP-1-binding sites (TGACATCA). These two proteins belong to a family of related transcription factors which contain similar domains required for protein dimerization and DNA binding but display different protein and DNA binding specificities. The basic region, required for DNA binding, is followed by a leucine zipper structure, a domain that mediates protein-protein interactions. To assess the role of these two domains in three related proteins, Fos, Jun, and CREB, we carried out extensive domain-swapping analysis. We found that (i) dimers formed by two Jun leucine zipper-containing proteins were unable to bind DNA as efficiently as a Fos-Jun combination, regardless of the source of the basic region; (ii) the Fos leucine zipper was unable to form either homo- or heterodimers with a chimeric protein containing a Fos leucine zipper; (iii) the Fos basic region was capable of binding to an AP-1 site; (iv) replacement of the Jun amino terminus with that of CREB had little effect on dimerization, whereas replacement with the amino terminus of Fos disrupted both protein-protein and protein-DNA interactions; (v) changes in relative affinities of the Fos and Jun basic regions for the AP-1 element were dependent on the secondary contributions of amino-terminal residues; and (vi) the Fos-Jun chimeric constructs cooperated in transcriptional transactivation of the Jun promoter in NIH 3T3 cells.

Protein-protein interactions and membrane localization of the human organic solute transporter

2007 ◽  
Vol 292 (6) ◽  
pp. G1586-G1593 ◽  
Author(s):  
An-Qiang Sun ◽  
Natarajan Balasubramaniyan ◽  
Ke Xu ◽  
Chuan Ju Liu ◽  
Vijaya M. Ponamgi ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Amino Acid ◽  
Protein Interactions ◽  
Membrane Localization ◽  
Protein Protein Interactions ◽  
Amino Terminal ◽  
Organic Solute Transporter ◽  
Organic Solute ◽  
Carboxyl Terminal ◽  
Solute Transporter

Two proteins that mediate bile acid export from the ileal enterocyte, organic solute transporter (OST)-α and -β, have recently been identified. It is unclear whether these two proteins associate directly and how they interact to mediate transport function and membrane localization. In this study, the protein-protein interactions, transport functions, and membrane localization of human (h)OST-α and -β proteins were examined. The results demonstrated that coexpression of hOST-α and -β in transfected cells resulted in a three- to fivefold increase of the initial rate of taurocholate influx or efflux compared with cells expressing each protein individually and nontransfected cells. Confocal microscopy demonstrated plasma membrane colocalization of hOST-α and -β proteins in cells cotransfected with hOST-α and -β cDNAs. Protein-protein interactions between hOST-α and -β were demonstrated by mammalian two-hybrid and coimmunoprecipitation analyses. Truncation of the amino-terminal 50 amino acid extracellular residues of hOST-α abolished its interaction with hOST-β and led to an intracellular accumulation of the two proteins and to only background levels of taurocholate transport. In contrast, carboxyl-terminal 28 amino acid truncated hOST-α still interacted with hOST-β, and majority of this cytoplasmic tail-truncated protein was expressed on the basolateral membrane when it was stably cotransfected with hOST-β protein in Madin-Darby canine kidney cells. In summary, hOST-α and -β proteins are physically associated. The intracellular carboxyl-terminal domain of hOST-α is not essential for this interaction with hOST-β. The extracellular amino-terminal fragment of hOST-α may contain important information for the assembly of the heterodimer and trafficking to the plasma membrane.

A mutation outside the two zinc fingers of ADR1 can suppress defects in either finger

1992 ◽  
Vol 12 (12) ◽  
pp. 5758-5767
Author(s):  
S Camier ◽  
N Kacherovsky ◽  
E T Young
Keyword(s):  
Dna Binding ◽  
Protein Interactions ◽  
Zinc Fingers ◽  
Wild Type ◽  
Protein Protein Interactions ◽  
Site Mutation ◽  
Binding Motifs ◽  
Amino Terminal ◽  
Sequence Homologies ◽  
In The Wild

A second-site mutation that restored DNA binding to ADR1 mutants altered at different positions in the two zinc fingers was identified. This mutation (called IS1) was a conservative change of arginine 91 to lysine in a region amino terminal to the two zinc fingers and known from previous experiments to be necessary for DNA binding. IS1 increased binding to the UAS1 sequence two- to sevenfold for various ADR1 mutants and twofold for wild-type ADR1. The change of arginine 91 to glycine decreased binding twofold, suggesting that this arginine is involved in DNA binding in the wild-type protein. The increase in binding by IS1 did not involve protein-protein interactions between the two ADR1 monomers, nor did it require the presence of the sequences flanking UAS1. However, the effect of IS1 was influenced by the sequence of the first finger, suggesting that interactions between the region amino terminal to the fingers and the fingers themselves could exist. A model for the role of the amino-terminal region based on these results and sequence homologies with other DNA-binding motifs is proposed.

scholarly journals The Amino Terminus of Bacteriophage λ Integrase Is Involved in Protein-Protein Interactions during Recombination

2000 ◽  
Vol 182 (4) ◽  
pp. 1024-1034 ◽  
Author(s):  
Lea Jessop ◽  
Troy Bankhead ◽  
David Wong ◽  
Anca M. Segall
Keyword(s):  
Protein Interactions ◽  
Protein Protein Interactions ◽  
Site Specific ◽  
Site Specific Recombination ◽  
Amino Terminal ◽  
Terminal Domain ◽  
Protein Dna Interactions ◽  
Bacteriophage Lambda Integrase ◽  
Amino Terminal Domain ◽  
Genetic Assay

ABSTRACT Bacteriophage lambda integrase (Int) catalyzes at least four site-specific recombination pathways between pairs of attachment (att) sites. Protein-protein contacts between monomers of Int are presumed to be important for these site-specific recombination events for several reasons: Int binds to the att sites cooperatively, catalytic Int mutants can complement each other for strand cleavage, and crystal structures for two other recombinases in the Int family (Cre from phage P1 and Int from Haemophilus influenzae phage HP1) show extensive protein-protein contacts between monomers. We have begun to investigate interactions between Int monomers by three approaches. First, using a genetic assay, we show that regions of protein-protein interactions occur throughout Int, including in the amino-terminal domain. This domain was previously thought to be important only for high-affinity protein-DNA interactions. Second, we have found that an amino-terminal His tag reduces cooperative binding to DNA. This disruption in cooperativity decreases the stable interaction of Int with core sites, where catalysis occurs. Third, using protein-protein cross-linking to investigate the multimerization of Int during recombination, we show that Int predominantly forms dimers, trimers, and tetramers. Moreover, we show that the cysteine at position 25 is present at or near the interface between monomers that is involved in the formation of dimers and tetramers. Our evidence indicates that the amino-terminal domain of Int is involved in protein-protein interactions that are likely to be important for recombination.

scholarly journals Assembly of the Epstein–Barr virus BBLF4, BSLF1 and BBLF2/3 proteins and their interactive properties

1999 ◽  
Vol 80 (11) ◽  
pp. 2879-2887 ◽  
Author(s):  
Naoaki Yokoyama ◽  
Ken Fujii ◽  
Mineo Hirata ◽  
Katsuyuki Tamai ◽  
Tohru Kiyono ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Epstein Barr Virus ◽  
Insect Cells ◽  
Recombinant Baculoviruses ◽  
Viral Gene ◽  
Replication Proteins ◽  
Protein Protein Interactions ◽  
Barr Virus ◽  
Epstein Barr

Epstein–Barr virus (EBV) encodes putative helicase–primase proteins BBLF4, BSLF1 and BBLF2/3, which are essential for the lytic phase of viral DNA replication. The BSLF1, BBLF4 and BBLF2/3 proteins were expressed in B95-8 cells after induction of a virus productive cycle, possessing apparent molecular masses of 89 kDa, 90 kDa and 80 kDa, respectively. The anti-BSLF1 or anti-BBLF2/3 protein-specific antibody, which recognizes its target protein in both Western blotting and immunoprecipitation analyses, immunoprecipitated all of the BSLF1, BBLF4 and BBLF2/3 proteins from the extract of the cells with a virus productive cycle, indicating that these viral proteins are assembled together in vivo . To characterize their protein–protein interactions in detail, recombinant baculoviruses capable of expressing each of these viral gene products in insect cells were constructed. The assembly of the three virus replication proteins was reproduced in insect cells co- infected with the three recombinant baculoviruses, indicating that complex formation does not require other EBV replication proteins. Furthermore, experiments performed by using the extracts from insect cells co-infected with each pair of the recombinant viruses demonstrated that the BSLF1 protein could interact separately with both the BBLF4 and BBLF2/3 proteins and that the BBLF2/3 protein also interacted with the BBLF4 protein. These observations strongly suggest that within the BBLF4–BSLF1–BBLF2/3 complex each component interacts directly with the other two, resulting in helicase–primase enzyme activity.

scholarly journals Formation of Polyomavirus-Like Particles with Different VP1 Molecules That Bind the Urokinase Plasminogen Activator Receptor

2003 ◽  
Vol 77 (21) ◽  
pp. 11491-11498 ◽  
Author(s):  
Young C. Shin ◽  
William R. Folk
Keyword(s):  
Plasminogen Activator ◽  
Self Assembly ◽  
Insect Cells ◽  
Urokinase Plasminogen Activator ◽  
Animal Cells ◽  
Urokinase Plasminogen Activator Receptor ◽  
Flag Epitope ◽  
Related Phage ◽  
Surface Receptors ◽  
Amino Terminal

ABSTRACT Icosahedral virus-like particles formed by the self-assembly of polyomavirus capsid proteins (Py-VLPs) can serve as useful nanostructures for delivering nucleic acids, proteins, and pharmaceuticals into animal cells and tissues. Four predominant surface-exposed loops in the VP1 structure offer potential sites to display sequences that might contribute new targeting specificities. Introduction into each of these loops of sequences derived from the amino-terminal fragment of urokinase plasminogen activator (uPA) or a related phage display peptide reduced the solubility of VP1 molecules when expressed in insect cells, and insertions into the EF loop reduced VP1 solubility least. Coexpression in insect cells of the uPA-VP1 molecules and VP1 containing a FLAG epitope in the HI loop permitted the formation of heterotypic Py-VLPs containing uPA-VP1 and FLAG-VP1. These heterotypic VLPs bound to uPAR on the surfaces of animal cells. Heterotypic Py-VLPs containing ligands for multiple cell surface receptors should be useful for targeting specific cells and tissues.

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