Visualisierung von Protein-Protein-Wechselwirkung in Kern- und Cytoplasma-Fraktionen durch Co-Immunpräzipitation und<em> In Situ</em> Nähe Ligatur Assay
Summary
Protein-protein interactions can occur in both the nucleus and the cytoplasm of a cell. To investigate these interactions, traditional co-immunoprecipitation and modern proximity ligation assay are applied. In this study, we compare these two methods to visualize the distribution of NF90-RBM3 interactions in the nucleus and the cytoplasm.
Abstract
Protein-protein interactions are involved in thousands of cellular processes and occur in distinct spatial context. Traditionally, co-immunoprecipitation is a popular technique to detect protein-protein interactions. Subsequent Western blot analysis is the most common method to visualize co-immunoprecipitated proteins. Recently, the proximity ligation assay has become a powerful tool to visualize protein-protein interactions in situ and provides the possibility to quantify protein-protein interactions by this method. Similar to conventional immunocytochemistry, the proximity ligation assay technique is also based on the accessibility of primary antibodies to the antigens, but in contrast, proximity ligation assay detects protein-protein interactions with a unique technique involving rolling-circle PCR, while conventional immunocytochemistry only shows co-localization of proteins.
Nuclear factor 90 (NF90) and RNA-binding motif protein 3 (RBM3) have been previously demonstrated as interacting partners. They are predominantly localized in the nucleus, but also migrate into the cytoplasm and regulate signaling pathways in the cytoplasmic compartment. Here, we compared NF90-RBM3 interaction in both the nucleus and the cytoplasm by co-immunoprecipitation and proximity ligation assay. In addition, we discussed the advantages and limitations of these two techniques in visualizing protein-protein interactions in respect to spatial distribution and the properties of protein-protein interactions.
Introduction
Nuclear factor 90 (NF90) ist ein Multi-Isoform – Proteins mit zahlreichen Funktionen , einschließlich der Reaktion auf eine virale Infektion, die Regulierung von Interleukin-2 post-Transkription und Regulierung der miRNA Biogenese 1-3. RBM3 ist ein RNA-bindendes Protein, involviert in Translation und miRNA Biogenese und kann durch verschiedene Stressoren einschließlich Hypothermie und Hypoxie 4-6 induziert werden. Vor kurzem fanden wir NF90 und RBM3 in einem Proteinkomplex 7. Das Zusammenspiel von NF90 und RBM3 ist essentielles Protein – Kinase – RNA-ähnliche Endoplasmatischen Retikulum – Kinase (PERK) Aktivität in ungefalteten Protein – Reaktion 7 zu modulieren. Sowohl NF90 und RBM3 befinden sich überwiegend im Kern aber einem geringen Anteil an NF90 und RBM3 Shuttle in das Zytoplasma und binden dort miteinander für bestimmte Funktionen, beispielsweise PERK Aktivität zu regulieren. Daher ist es wichtig, die Verteilung von NF90-RBM3 Wechselwirkungen in dem subzellulären Kompartiment zu visualisieren, die anzeigen kannihre verschiedenen Rollen in den jeweiligen Fach.
Vor Jahrzehnten, Hefe – Zwei – Hybrid (Y2H) wurde die Wechselwirkung zwischen zwei Proteinen 8 zu erkennen , entwickelt. Aufgrund künstliche Konstruktion von Fusionsproteinen, falsch-positive Ergebnisse haben die Anwendung dieses Verfahrens beschränkt. Für eine lange Zeit, Co-Immunpräzipitation war das Haupt Technik Protein-Protein – Wechselwirkungen, insbesondere in endogener Bedingungen 9 zu analysieren. Um die Co-immunpräzipitiert Proteinkomplex zu analysieren, Western-Blot ist die bequemste Methode, während der Massenspektrometrie verwendet wird, wenn Super Empfindlichkeit und Genauigkeit erwünscht sind. In den letzten Jahren Proximity Ligation Assay wurde als ein neues Verfahren entwickelt worden , Protein-Protein – Wechselwirkungen in beiden Zellen und Gewebe in situ 10,11 zu erkennen.
Hier verglichen wir die beliebtesten Coimmunpräzipitation Verfahren und relativ neuartige Nähe Ligatur Testverfahren in NF9 Erfassung0-RBM3 Interaktion in subzellulären Fraktionen. Wir diskutierten auch die Vorteile und Grenzen beider Techniken.
Protocol
Representative Results
Discussion
Es gibt mehrere Vorteile sowie Nachteile für beide Methoden. Als eine relativ neue Technik, ein offensichtlicher Vorteil Proximity Ligation Assay ist die Durchführbarkeit Protein-Protein-Wechselwirkungen auf Einzelzellebene statt einer Charge von heterogenen Zellen aufzuklären. Bilder mit hoher Auflösung und Größe (zB durch konfokale Mikroskop) bieten die Möglichkeit zur Quantifizierung von einzelnen fluoreszierenden Flecken zu zählen. Im Gegensatz dazu kann die herkömmliche Kombination von Co-Immunpr?…
Divulgations
The authors have nothing to disclose.
Acknowledgements
This study was supported by the Swiss National Science Foundation (SNSF, 31003A_163305).
Materials
| Dulbecco's Modified Eagle’s Medium (DMEM) | Sigma | D6429 | High glucose 4500 mg/L |
| Fetal bovine serum (FBS) | Gibco, Thermo Fisher Scientific | 10270106 | |
| Penicillin-Streptomycin (PenStrep) | BioConcept | 4-01F00-H | |
| NE-PER Nuclear and Cytoplasmic Extraction Reagents | Thermo Fisher Scientific | 78833 | |
| 1,4-Dithiothreitol (DTT) | Carl Roth | 6908.3 | |
| Dynabeads Protein G | Novex, Thermo Fisher Scientific | 10003D | |
| DRBP76 (NF90/NF110) antibody | BD Transduction Laboratories | 612154 | use 1:1000 for WB and 1:100 for ICC/PLA |
| RBM3 antibody | ProteinTech | 14363-1-AP | use 1:1000 for WB and 1:100 for ICC/PLA |
| Lamin A/C antibody | Cell Signaling Technology | #2032 | use 1:1000 for WB |
| anti-GAPDH antibody | Abcam | ab8245 | use 1:1000 for WB |
| normal rabbit IgG | Santa Cruz | sc-2027 | |
| anti-rabbit IgG, HRP-lined secodary antiboy | Cell Signaling Technology | #7074 | use 1:5000 for WB |
| anti-mouse HRP secondary antibody | Carl Roth | 4759.1 | use 1:5000 for WB |
| Clarity Western ECL Blotting Substrate | Bio-Rad | #1705060 | |
| NuPAGE Novex 4-12% Bis-Tris Gel | Novex, Thermo Fisher Scientific | NP0321BOX | |
| NuPAGE LDS Sample Buffer (4x) | Novex, Thermo Fisher Scientific | NP0007 | |
| 1,4-Dithiothreitol (DTT) | CarlRoth | 6908.1 | |
| NuPAGE MES SDS Running Buffer (20x) | Novex, Thermo Fisher Scientific | NP0002 | |
| NuPAGE Transfer Buffer (20x) | Novex, Thermo Fisher Scientific | NP00061 | |
| Amersham Hypond P 0.2 PVDF membrane | GE Healthcare Life Sciences | 10600021 | |
| Super RX X-ray film | Fujifilm | 4741029230 | |
| Poly-D-Lysine 8 Well Culture Slide | Corning BioCoat | 354632 | |
| Paraformaldehyde (PFA) | Sigma | P6148 | |
| Normal goat serum (NGS) | Gibco, Thermo Fisher Scientific | PCN5000 | |
| Goat anti-mouse IgG (H+L Antibody), Alexa Fluor 488 conjugate | Thermo Fisher Scientific | A-11001 | |
| Goat anti-rabbit IgG (H+L Antibody), Alexa Fluor 568 conjugate | Thermo Fisher Scientific | A-11011 | |
| 4′, 6-Diamidin-2-phenylindol (DAPI) | Sigma | D9542 | |
| Duolink PLA probe Anti-mouse PLUS | Sigma | DUO92001 | |
| Duolink PLA probe Anti-rabbit MINUS | Sigma | DUO92005 | |
| Duolink Detection Reagents Red | Sigma | DUO92008 | |
| Duolink Wash Buffers Fluorescence | Sigma | DUO82049 | |
| Duolink Mounting Medium with DAPI | Sigma | DUO82040 | |
| Mowiol 4-88 | Sigma | 81381 | |
| Microscope | Olympus | AX-70 | |
| CCD camera | SPOT | Insight 2MP Firewire | |
| X-ray film | Fujifilm | Super RX | |
| Film processing machine | Fujifilm | FPM-100A |
References
- Patiño, C., Haenni, A. L., Urcuqui-Inchima, S. NF90 isoforms, a new family of cellular proteins involved in viral replication?. Biochimie. 108, 20-24 (2015).
- Shim, J., Lim, H., R Yates, J., Karin, M. Nuclear export of NF90 is required for interleukin-2 mRNA stabilization. Mol Cell. 10 (6), 1331-1344 (2002).
- Sakamoto, S., et al. The NF90-NF45 complex functions as a negative regulator in the microRNA processing pathway. Mol Cell Biol. 29 (13), 3754-3769 (2009).
- Dresios, J., et al. Cold stress-induced protein Rbm3 binds 60S ribosomal subunits, alters microRNA levels, and enhances global protein synthesis. Proc Natl Acad Sci. 102 (6), 1865-1870 (2005).
- Danno, S., Itoh, K., Matsuda, T., Fujita, J. Decreased expression of mouse Rbm3, a cold-shock protein, in Sertoli cells of cryptorchid testis. Am J Pathol. 156 (5), 1685-1692 (2000).
- Wellmann, S., et al. Oxygen-regulated expression of the RNA-binding proteins RBM3 and CIRP by a HIF-1-independent mechanism. J Cell Sci. 117 (Pt 9), 1785-1794 (2004).
- Zhu, X., Zelmer, A., Kapfhammer, J. P., Wellmann, S. Cold-inducible RBM3 inhibits PERK phosphorylation through cooperation with NF90 to protect cells from endoplasmic reticulum stress. FASEB J. 30 (2), 624-634 (2016).
- Fields, S., Song, O. A novel genetic system to detect protein-protein interactions. Nature. 340 (6230), 245-246 (1989).
- Verhelst, J., De Vlieger, D., Saelens, X. Co-immunoprecipitation of the Mouse Mx1 Protein with the Influenza A Virus Nucleoprotein. J Vis Exp. (98), (2015).
- Söderberg, O., et al. Direct observation of individual endogenous protein complexes in situ by proximity ligation. Nat Methods. 3 (12), 995-1000 (2007).
- Jarvius, M., et al. In situ detection of phosphorylated platelet-derived growth factor receptor beta using a generalized proximity ligation method. Mol Cell Proteomics. 6 (9), 1500-1509 (2007).
- Liu, C. H., et al. Analysis of protein-protein interactions in cross-talk pathways reveals CRKL protein as a novel prognostic marker in hepatocellular carcinoma. Mol Cell Proteomics. 12 (5), 1335-1349 (2013).
