-
- Reactivity
- Various Species
- Application
- Activation (Act)
- Sample Type
- Cell Lysate
- Characteristics
- RhoA Activation Assay Kit utilizes Rhotekin RBD Agarose beads to selectively isolate and pull-down the active form of Rho from purified samples or endogenous lysates. Subsequently, the precipitated GTP-Rho s detected by western blot analysis using an anti-RhoA specific monoclonal antibody (see Figure 3 and Assay Principle). RhoA Activation Assay Kit provides a simple and fast tool to monitor the activation of RhoA. The kit includes easily identifiable Rhotekin RBD Agarose beads (see Figure 1), pink in color, and a RhoA Immunoblot Positive Control for quick RhoA identification. Each kit provides sufficient quantities to perform 20 assays. Figure 1:Rhotekin RBD Agarose beads, in color, are easy to visualize, minimizing potential loss during washes and aspirations.
- Components
-
- Rhotekin RBD Agarose : One vial - 800 μL of 50% slurry, 400 μg Rhotekin RBD in PBS containing 50% glycerol. Note: Agarose bead appears pink in color for easy identification, washing, and aspiration.
- 100X GTPγS : One vial - 50 μL of 10 mM GTPγS dissolved in sterile water.
- 100X GDP : One vial - 50 μL of 100 mM GDP dissolved in sterile water.
- 5X Assay/Lysis Buffer : One bottle - 30 mL of 125 mM HEPES, pH 7.5, 750 mM NaCl, 5% NP-40, 50 mM MgCl2, 5 mM EDTA, 10% Glycerol.
- Anti-RhoA, Mouse Monoclonal : One vial - 40 μL in PBS, pH 7.4, 0.05% NaN3, 0.1% BSA. Note: This monoclonal antibody specifically reacts with human, mouse, and rat RhoA.
- RhoA Immunoblot Positive Control : One vial - 100 μL of partially purified, recombinant RhoA from E. coli (provided ready-to-use in 1X reducing SDS-PAGE Sample Buffer, pre-boiled).
- Material not included
-
- Stimulated and non-stimulated cell lysates
- RhoA activators
- Protease inhibitors
- 0.5 M EDTA in water
- 1 M MgCl2
- 30 °C incubator or water bath
- 4 °C tube rocker or shaker
- 2X reducing SDS-PAGE sample buffer
- Electrophoresis and immunoblotting systems
- Immunoblotting wash buffer such as TBST (10 mM Tris-HCl, pH 7.4, 0.15 M NaCl, 0.05 % Tween-20)
- Immunoblotting blocking buffer (TBST containing 5 % Non-fat Dry Milk)
- PVDF or nitrocellulose membrane
- Secondary Antibody
- ECL Detection Reagents 4
-
-
- Application Notes
- Optimal working dilution should be determined by the investigator.
- Comment
-
- Safe non-radioactive assay format
- Colored agarose beads allow visual check
- Fast results: 1 hour plus electrophoresis/blotting time
- Assay Time
- 1 h
- Reagent Preparation
-
- 1X Assay/Lysis Buffer: Mix the 5X Stock briefly and dilute to 1X in deionized water. Just prior to usage, add protease inhibitors such as 1 mM PMSF, 10 μg/mL leupeptin, and 10 μg/mL aprotinin.
- Sample Preparation
-
Note: It is advisable to use fresh cell lysates because GTP-RhoA is quickly hydrolyzed to GDP- RhoA, frozen lysates stored at -70 °C may be used. Performing steps at 4 °C or on ice may reduce hydrolysis. Avoid multiple freeze/thaw cycles of lysates.
I. Adherent Cells
- Culture cells to approximately 80-90 % confluence. Stimulate cells with RhoA activator(s) as desired.
- Aspirate the culture media and wash twice with ice-cold PBS.
- Completely remove the final PBS wash and add ice-cold 1X Assay/Lysis Buffer to the cells (0.5 - 1 mL per 100 mm tissue culture plate).
- Place the culture plates on ice for 10-20 minutes.
- Detach the cells from the plates by scraping with a cell scraper.
- Transfer the lysates to appropriate size tubes and place on ice.
- If nuclear lysis occurs, the cell lysates may become very viscous and difficult to pipette. If this occurs, lysates can be passed through a 271/2-gauge syringe needle 3-4 times to shear the genomic DNA.
- Clear the lysates by centrifugation for 10 minutes (14,000 x g at 4 °C).
- Collect the supernatant and store samples on ice for immediate use, or snap freeze and store at - 70 °C for future use.
- Proceed to GTPγS/GDP Loading for positive and negative controls, or Pull-Down Assay.
II. Suspension Cells
- Culture cells and stimulate with RhoA activator(s) as desired.
- Perform a cell count, and then pellet the cells by centrifugation.
- Aspirate the culture media and wash twice with ice-cold PBS.
- Completely remove the final PBS wash and add ice-cold 1X Assay/Lysis Buffer to the cell pellet (0.5 - 1 mL per 1 x 107 cells).
- Lyse the cells by repeated pipetting. 5
- Transfer the lysates to appropriate size tubes and place on ice.
- If nuclear lysis occurs, the cell lysates may become very viscous and difficult to pipette. If this occurs, lysates can be passed through a 271/2-gauge syringe needle 3-4 times to shear the genomic DNA.
- Clear the lysates by centrifugation for 10 minutes (14,000 x g at 4 °C).
- Collect the supernatant and store samples on ice for immediate use, or snap freeze and store at - 70 °C for future use.
- Proceed to GTPγS/GDP Loading for positive and negative controls, or Pull-Down Assay.
- Assay Procedure
-
Important Note: Before running any Small GTPase pulldown assay, it is always a good practice to run a Western Blot directly on the cell lysate using the antibody provided in this kit. For example: load 5 μg, 10 μg and 20 μg of lysate onto an SDS-PAGE gel, transfer and blot. When proceeding with the pulldown assay, use 100-times the amount of lysate that gave you a clear band of your desired small GTPase in the direct Western blot. For example: if the 5 μg band was faint but the 10 μg band was clear and strong, use 100 x 10 μg = 1 mg of lysate in the assay. Using sufficient lysate in the pulldown assay is critical to success.
I. GTPγS/GDP Loading (Positive and Negative Controls) Note: Samples that will not be GTPγS/GDP loaded may be kept on ice during the loading of controls.
- Aliquot 0.5 - 1 mL of each cell lysate to two microcentrifuge tubes. Note: Typical protein content/sample is > 0.5 mg.
- Adjust the volume of each sample to 1 mL with 1X Assay Lysis Buffer.
- Add 20 μL of 0.5 M EDTA to each sample.
- Add 10 μL of 100X GTPγS to one tube (positive control) and 10 μL of 100X GDP to the other tube (negative control). Mix and label each tube appropriately.
- Incubate the tubes for 30 minutes at 30 °C with agitation.
- Stop the loading by adding 65 μL of 1 M MgCl2 to each tube. Mix and place tubes on ice.
- Continue with Pull-Down assay.
II. RhoA Pull-Down Assay
- Aliquot 0.5 - 1 mL of cell lysate (treated with RhoA activators or untreated) to a microcentrifuge tube.
- Adjust the volume of each sample to 1 mL with 1X Assay Lysis Buffer.
- Thoroughly resuspend the Rhotekin RBD Agarose bead slurry by vortexing or titurating.
- Quickly add 40 μL of resuspended bead slurry to each tube (including GTPγS/GDP controls).
- Incubate the tubes at 4 °C for 1 hour with gentle agitation.
- Pellet the beads by centrifugation for 10 seconds at 14,000 x g. 6
- Aspirate and discard the supernatant, making sure not to disturb/remove the bead pellet.
- Wash the bead 3 times with 0.5 mL of 1X Assay Buffer, centrifuging and aspirating each time.
- After the last wash, pellet the beads and carefully remove all the supernatant.
- Resuspend the bead pellet in 40 μL of 2X reducing SDS-PAGE sample buffer.
- Boil each sample for 5 minutes.
- Centrifuge each sample for 10 seconds at 14,000 x g.
III. Electrophoresis and Transfer
- Load 20 μL/well of pull-down supernatant to a polyacrylamide gel. Also, it's recommended to include a pre-stained MW standard (as an indicator of a successful transfer in step 3). Note: If desired, 10 μL/well of RhoA Immunoblot Positive Control (provided ready-to-use, pre- boiled) can be added as an immunoblot positive control.
- Perform SDS-PAGE as per the manufacturer's instructions.
- Transfer the gel proteins to a PVDF or nitrocellulose membrane as per the manufacturer's instructions.
IV. Immunoblotting and Detection (all steps are at room temperature, with agitation)
- Following the electroblotting step, immerse the PVDF membrane in 100 % Methanol for 15 seconds, and then allow it to dry at room temperature for 5 minutes. Note: If Nitrocellulose is used instead of PVDF, this step should be skipped.
- Block the membrane with 5 % non-fat dry milk in TBST for 1 hr at room temperature with constant agitation. Incubate the membrane with Anti-RhoA Antibody, freshly diluted 1:200 to 1:1000 in 5 % non- fat dry milk/TBST, for 1-2 hr at room temperature with constant agitation. Note: To conserve antibody, incubations should be performed in a plastic bag.
- Wash the blotted membrane three times with TBST, 5 minutes each time.
- Incubate the membrane with a secondary antibody (e.g. Goat Anti-Mouse IgG, HRP- conjugate), freshly diluted in 5 % non-fat dry milk/TBST, for 1 hr at room temperature with constant agitation.
- Wash the blotted membrane three times with TBST, 5 minutes each time.
- Use the detection method of your choice. We recommend enhanced chemiluminescence reagents from Pierce. 7
- Restrictions
- For Research Use only
-
- Handling Advice
- Avoid multiple freeze/thaw cycles.
- Storage
- -20 °C
- Storage Comment
- Store all kit components at -20°C. The 5X Assay/Lysis Buffer may be stored at either -20°C or 4°C. Avoid multiple freeze/thaw cycles.
-
-
Epigenetic silencing of TPM2 contributes to colorectal cancer progression upon RhoA activation." in: Tumour biology, Vol. 37, Issue 9, pp. 12477-12483, (2016) (PubMed).
: "Distinctive and selective route of PI3K/PKCα-PKCδ/RhoA-Rac1 signaling in osteoclastic cell migration." in: Molecular and cellular endocrinology, Vol. 437, pp. 261-267, (2016) (PubMed).
: "The Role of IRE-XBP1 Pathway in Regulation of Retinal Pigment Epithelium Tight Junctions." in: Investigative ophthalmology & visual science, Vol. 57, Issue 13, pp. 5244-5252, (2016) (PubMed).
: "Down-regulation of 14-3-3 Zeta Inhibits TGF-?1-Induced Actomyosin Contraction in Human Trabecular Meshwork Cells Through RhoA Signaling Pathway." in: Investigative ophthalmology & visual science, Vol. 57, Issue 2, pp. 719-30, (2016) (PubMed).
: "Toll-like receptor 2 mediates vascular contraction and activates RhoA signaling in vascular smooth muscle cells from STZ-induced type 1 diabetic rats." in: Pflügers Archiv : European journal of physiology, (2015) (PubMed).
: "piggyBac insertional mutagenesis screen identifies a role for nuclear RHOA in human ES cell differentiation." in: Stem cell reports, Vol. 4, Issue 5, pp. 926-38, (2015) (PubMed).
: "Actin-binding protein, Espin: a novel metastatic regulator for melanoma." in: Molecular cancer research : MCR, Vol. 12, Issue 3, pp. 440-6, (2014) (PubMed).
: "Ionizing radiation-inducible miR-494 promotes glioma cell invasion through EGFR stabilization by targeting p190B rhoGAP." in: Biochimica et biophysica acta, Vol. 1843, Issue 3, pp. 508-16, (2014) (PubMed).
: "DLC1 suppresses NF-?B activity in prostate cancer cells due to its stabilizing effect on adherens junctions." in: SpringerPlus, Vol. 3, pp. 27, (2014) (PubMed).
: "Resveratrol prevents AngII-induced hypertension via AMPK activation and RhoA/ROCK suppression in mice." in: Hypertension research : official journal of the Japanese Society of Hypertension, Vol. 37, Issue 9, pp. 803-10, (2014) (PubMed).
: "Nitric oxide increases the invasion of pancreatic cancer cells via activation of the PI3K-AKT and RhoA pathways after carbon ion irradiation." in: FEBS letters, Vol. 588, Issue 17, pp. 3240-50, (2014) (PubMed).
: "SDF-1? stiffens myeloma bone marrow mesenchymal stromal cells through the activation of RhoA-ROCK-Myosin II." in: International journal of cancer, Vol. 136, Issue 5, pp. E219-29, (2014) (PubMed).
: "GluN3A expression restricts spine maturation via inhibition of GIT1/Rac1 signaling." in: Proceedings of the National Academy of Sciences of the United States of America, Vol. 110, Issue 51, pp. 20807-12, (2013) (PubMed).
: "Wnt/?-catenin pathway is regulated by PITX2 homeodomain protein and thus contributes to the proliferation of human ovarian adenocarcinoma cell, SKOV-3." in: The Journal of biological chemistry, Vol. 288, Issue 6, pp. 4355-67, (2013) (PubMed).
: "DLC1 interaction with ?-catenin stabilizes adherens junctions and enhances DLC1 antioncogenic activity." in: Molecular and cellular biology, Vol. 32, Issue 11, pp. 2145-59, (2012) (PubMed).
: "Integrity of SOS1/EPS8/ABI1 tri-complex determines ovarian cancer metastasis." in: Cancer research, Vol. 70, Issue 23, pp. 9979-90, (2010) (PubMed).
: "Protein disulfide isomerase does not control recombinant IgG4 productivity in mammalian cell lines." in: Biotechnology and bioengineering, Vol. 105, Issue 4, pp. 770-9, (2010) (PubMed).
: "Expression of neuregulin 4 splice variants in normal human tissues and prostate cancer and their effects on cell motility." in: Endocrine-related cancer, Vol. 18, Issue 1, pp. 39-49, (2010) (PubMed).
: "The angiotensin II type 1 receptor induces membrane blebbing by coupling to Rho A, Rho kinase, and myosin light chain kinase." in: Molecular pharmacology, Vol. 77, Issue 6, pp. 903-11, (2010) (PubMed).
: "
-
Epigenetic silencing of TPM2 contributes to colorectal cancer progression upon RhoA activation." in: Tumour biology, Vol. 37, Issue 9, pp. 12477-12483, (2016) (PubMed).
-
- Background
- Small GTP-binding proteins (or GTPases) are a family of proteins that serve as molecular regulators in signaling transduction pathways. RhoA, a 21 kDa protein, regulating a variety of biological response pathways that include cell growth, cell transformation and tumor invasion. Like other small GTPases, RhoA regulates molecular events by cycling between an inactive GDP-bound form and an active GTP- bound form. In its active (GTP-bound) state, RhoA binds specifically to the Rho-binding domain (RBD) of Rhotekin to control downstream signaling cascades.
-