Filamin B Antibody (Rabbit mAb) [L9N6]

製品コード:F9861

印刷

生物学的記述

Specificity Filamin B Antibody (Rabbit mAb) [L9N6] detects endogenous levels of total Filamin B protein.
Background Filamin B (FLNB) is a large dimeric actin‑binding protein of the filamin family that crosslinks F‑actin into three‑dimensional networks and connects membrane receptors to the cytoskeleton, thereby coordinating mechanotransduction and signaling in skeletal, vascular and muscle tissues. The protein contains an N‑terminal actin‑binding domain followed by a series of Ig‑like repeats that form flexible rod segments, with dimerization at the C‑terminus creating V‑shaped structures capable of orthogonal actin branching and of presenting multiple binding sites for transmembrane proteins and signaling factors. Through these domains, FLNB anchors integrins and other receptors to actin filaments and acts as a scaffold for complexes that regulate cell shape, migration and differentiation, with filamin–refilin interactions providing an additional layer of control over actin crosslinking properties and higher‑order network remodeling during development. In skeletal development, FLNB is a key regulator of chondrocyte progenitor differentiation and endochondral ossification, and both biallelic loss‑of‑function and gain‑of‑function FLNB mutations cause distinct groups of skeletal dysplasias such as spondylocarpotarsal synostosis, Larsen syndrome, atelosteogenesis and boomerang dysplasia, reflecting either loss of repressive function on TGF‑β signaling or disruption of mechanosensory properties. FLNB also interacts physically with Formin 1 and other actin regulators to coordinate chondrocyte polarity and migration, and pathogenic mutations in its actin‑binding domain, such as W148R, induce abnormal F‑actin clustering and cell dysmotility, linking precise actin tethering by FLNB to normal skeletal morphogenesis. In adult endothelial cells, FLNB is concentrated in the vascular endothelium and plays a crucial role in VEGF‑induced motility and angiogenesis: siRNA‑mediated FLNB depletion in human umbilical vein endothelial cells reduces VEGF‑driven migration and in vitro tube formation, increases substrate adhesion and focal adhesion density, and alters Rac‑1 localization and signaling. FLNB forms a signaling complex with Rac‑1 and its guanine nucleotide exchange factor Vav‑2 under basal conditions, and upon VEGF stimulation, this complex interacts with VEGFR2 and integrin αvβ5, facilitating Rac‑1 activation, downstream PAK4/5/6 signaling and actin remodeling required for efficient endothelial migration. FLNB also regulates the cell‑surface retention of sphingosine‑1‑phosphate receptor 1 (S1PR1) in endothelium, influencing vascular barrier function and homeostasis by controlling receptor trafficking at actin‑anchored membrane domains. In muscle, different FLNB splice variants show distinct subcellular localizations and effects on myotube morphology, and proteasomal degradation of FLNB by the ASB2β-containing SCF‑like ubiquitin ligase complex promotes muscle differentiation, indicating that FLNB levels and isoform composition modulate myogenesis. The ability of FLNB to crosslink actin, couple integrins and other receptors to the cytoskeleton, and participate in signaling assemblies with Rac‑1, Vav‑2, TGF‑β effectors and ubiquitin ligases defines it as a multifunctional structural and signaling hub.

使用情報

Application WB, IHC, IF, FCM Dilution
WB IHC IF FCM
1:1000 1:5000 1:50 1:500
Reactivity Mouse, Rat, Human
Source Rabbit Monoclonal Antibody MW 278 kDa
Storage Buffer PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN3
Storage
(from the date of receipt)
-20°C (avoid freeze-thaw cycles), 2 years
WB
Experimental Protocol:
 
Sample preparation
1. Tissue: Lyse the tissue sample by adding an appropriate volume of ice-cold Tris-Triton Lysis Buffer (containing Protease Inhibitor Cocktail),and homogenize the tissue at a low temperature or lyse it by sonication on ice, then incubate on ice for 30 minutes.
2. Adherent cell: Aspirate the culture medium and wash the cells with ice-cold PBS twice. Lyse the cells by adding an appropriate volume of Tris-Triton Lysis Buffer (containing Protease Inhibitor Cocktail) , sonicate to lyse the cells, and incubate on ice for 30 minutes.
3. Suspension cell: Transfer the culture medium to a pre-cooled centrifuge tube. Centrifuge and aspirate the supernatant. Wash the cells with ice-cold PBS twice. Lyse the cells by adding an appropriate volume of Tris-Triton Lysis Buffer (containing Protease Inhibitor Cocktail) , sonicate to lyse the cells, and incubate on ice for 30 minutes.
4. Place the lysate into a pre-cooled microcentrifuge tube. Centrifuge at 4°C for 15 min. Collect the supernatant;
5. Remove a small volume of lysate to determine the protein concentration;
6. Combine the lysate with protein loading buffer. Boil 20 µL sample under 95-100°C for 5 min. Centrifuge for 5 min after cool down on ice.
 
Electrophoretic separation
1. According to the concentration of extracted protein, load appropriate amount of protein sample and marker onto SDS-PAGE gels for electrophoresis. Recommended separating gel (lower gel) concentration: 5%. Reference Table for Selecting SDS-PAGE Separation Gel Concentrations
2. Power up 80V for 30 minutes. Then the power supply is adjusted (110 V~150 V), the Marker is observed, and the electrophoresis can be stopped when the indicator band of the predyed protein Marker where the protein is located is properly separated. (Note that the current should not be too large when electrophoresis, too large current (more than 150 mA) will cause the temperature to rise, affecting the result of running glue. If high currents cannot be avoided, an ice bath can be used to cool the bath.)
 
Transfer membrane
1. Take out the converter, soak the clip and consumables in the pre-cooled converter;
2. Activate PVDF membrane with methanol for 1 min and rinse with transfer buffer;
3. Install it in the order of "black edge of clip - sponge - filter paper - filter paper - glue -PVDF membrane - filter paper - filter paper - sponge - white edge of clip";
4. The protein was electrotransferred to PVDF membrane. ( 0.45 µm PVDF membrane is recommended ) Reference Table for Selecting PVDF Membrane Pore Size Specifications
Recommended conditions for wet transfer: 250 mA, 180 min.
( Note that the transfer conditions can be adjusted according to the protein size. For high-molecular-weight proteins, a higher current and longer transfer time are recommended. However, ensure that the transfer tank remains at a low temperature to prevent gel melting.)
 
Block
1. After electrotransfer, wash the film with TBST at room temperature for 5 minutes;
2. Incubate the film in the blocking solution for 1 hour at room temperature;
3. Wash the film with TBST for 3 times, 5 minutes each time.
 
Antibody incubation
1. Use primary antibody dilution buffer to prepare the primary antibody working liquid (recommended dilution ratio for primary antibody 1:1000), gently shake and incubate with the film at 4°C overnight;
2. Wash the film with TBST 3 times, 5 minutes each time;
3. Add the secondary antibody to the blocking solution and incubate with the film gently at room temperature for 1 hour;
4. After incubation, wash the film with TBST 3 times for 5 minutes each time.
 
Antibody staining
1. Add the prepared ECL luminescent substrate (or select other color developing substrate according to the second antibody) and mix evenly;
2. Incubate with the film for 1 minute, remove excess substrate (keep the film moist), wrap with plastic film, and expose in the imaging system.
IHC
Experimental Protocol:
 
Deparaffinization/Rehydration
1. Deparaffinize/hydrate sections:
2. Incubate sections in three washes of xylene for 5 min each.
3. Incubate sections in two washes of 100% ethanol for 10 min each.
4. Incubate sections in two washes of 95% ethanol for 10 min each.
5. Wash sections two times in dH2O for 5 min each.
6.Antigen retrieval: For Citrate: Heat slides in a microwave submersed in 1X citrate unmasking solution until boiling is initiated; continue with 10 min at a sub-boiling temperature (95°-98°C). Cool slides on bench top for 30 min.
 
Staining
1. Wash sections in dH2O three times for 5 min each.
2. Incubate sections in 3% hydrogen peroxide for 10 min.
3. Wash sections in dH2O two times for 5 min each.
4. Wash sections in wash buffer for 5 min.
5. Block each section with 100–400 µl of blocking solution for 1 hr at room temperature.
6. Remove blocking solution and add 100–400 µl primary antibody diluent in to each section. Incubate overnight at 4°C.
7. Remove antibody solution and wash sections with wash buffer three times for 5 min each.
8. Cover section with 1–3 drops HRPas needed. Incubate in a humidified chamber for 30 min at room temperature.
9. Wash sections three times with wash buffer for 5 min each.
10. Add DAB Chromogen Concentrate to DAB Diluent and mix well before use.
11. Apply 100–400 µl DAB to each section and monitor closely. 1–10 min generally provides an acceptable staining intensity.
12. Immerse slides in dH2O.
13. If desired, counterstain sections with hematoxylin.
14. Wash sections in dH2O two times for 5 min each.
15. Dehydrate sections: Incubate sections in 95% ethanol two times for 10 sec each; Repeat in 100% ethanol, incubating sections two times for 10 sec each; Repeat in xylene, incubating sections two times for 10 sec each.
16. Mount sections with coverslips and mounting medium.
 
IF
Experimental Protocol:
 
Sample Preparation
1. Adherent Cells: Place a clean, sterile coverslip in a culture dish. Once the cells grow to near confluence as a monolayer, remove the coverslip for further use.
2. Suspension Cells: Seed the cells onto a clean, sterile slide coated with poly-L-lysine.
3. Frozen Sections: Allow the slide to thaw at room temperature. Wash it with pure water or PBS for 2 times, 3 minutes each time.
4. Paraffin Sections: Deparaffinization and rehydration. Wash the slide with pure water or PBS for 3 times, 3 minutes each time. Then perform antigen retrieval.
 
Fixation
1. Fix the cell coverslips/spots or tissue sections at room temperature using a fixative such as 4% paraformaldehyde (4% PFA) for 10-15 minutes.
2. Wash the sample with PBS for 3 times, 3 minutes each time.
 
Permeabilization
1.Add a detergent such as 0.1–0.3% Triton X-100 to the sample and incubate at room temperature for 10–20 minutes.
(Note: This step is only required for intracellular antigens. For antigens expressed on the cell membrane, this step is unnecessary.)
Wash the sample with PBS for 3 times, 3 minutes each time.
 
Blocking
Add blocking solution and incubate at room temperature for at least 1 hour. (Common blocking solutions include: serum from the same source as the secondary antibody, BSA, or goat serum.)
Note: Ensure the sample remains moist during and after the blocking step to prevent drying, which can lead to high background.
 
Immunofluorescence Staining (Day 1)
1. Remove the blocking solution and add the diluted primary antibody.
2. Incubate the sample in a humidified chamber at 4°C overnight.
 
Immunofluorescence Staining (Day 2)
1. Remove the primary antibody and wash with PBST for 3 times, 5 minutes each time.
2. Add the diluted fluorescent secondary antibody and incubate in the dark at 4°C for 1–2 hours.
3. Remove the secondary antibody and wash with PBST for 3 times, 5 minutes each time.
4. Add diluted DAPI and incubate at room temperature in the dark for 5–10 minutes.
5. Wash with PBST for 3 times, 5 minutes each time.
 
Mounting
1. Mount the sample with an anti-fade mounting medium.
2. Allow the slide to dry at room temperature overnight in the dark.
3. Store the slide in a slide storage box at 4°C, protected from light.
 

References

  • https://pubmed.ncbi.nlm.nih.gov/20110358/
  • https://pubmed.ncbi.nlm.nih.gov/28739045/

Application Data

WB

Validated by Selleck

  • F9861-wb.gif
    Lane 1: A-204, Lane 2: 293T, Lane 3: A375, Lane 4: HT-1080