GRK2 (Phospho-Ser685)Colorimetric Cell-Based ELISA Kit (CBCAB00152)

Product Name:	GRK2 (Phospho-Ser685)Colorimetric Cell-Based ELISA Kit
Product Code:	CBCAB00152
ELISA Type:	Cell-Based
Target:	GRK2 (Phospho-Ser685)
Reactivity:	Human, Mouse, Rat
Dynamic Range:	> 5000 Cells
Detection Method:	Colorimetric 450 nm
Format:	2 x 96-Well Microplates

The GRK2 (Phospho-Ser685) Colorimetric Cell-Based ELISA Kit is a convenient, lysate-free, high throughput and sensitive assay kit that can detect GRK2 protein phosphorylation and expression profile in cells. The kit can be used for measuring the relative amounts of phosphorylated GRK2 in cultured cells as well as screening for the effects that various treatments, inhibitors (ie. siRNA or chemicals), or activators have on GRK2 phosphorylation.

Qualitative determination of GRK2 (Phospho-Ser685) concentration is achieved by an indirect ELISA format. In essence, GRK2 (Phospho-Ser685) is captured by GRK2 (Phospho-Ser685)-specific primary antibodies while the HRP-conjugated secondary antibodies bind the Fc region of the primary antibody. Through this binding, the HRP enzyme conjugated to the secondary antibody can catalyze a colorimetric reaction upon substrate addition. Due to the qualitative nature of the Cell-Based ELISA, multiple normalization methods are needed:

1.	A monoclonal antibody specific for human GAPDH is included to serve as an internal positive control in normalizing the target absorbance values.
2.	Following the colorimetric measurement of HRP activity via substrate addition, the Crystal Violet whole-cell staining method may be used to determine cell density. After staining, the results can be analysed by normalizing the absorbance values to cell amounts, by which the plating difference can be adjusted.

Database Information:	Gene ID: 156, UniProt ID: P25098, OMIM: 109635, Unigene: Hs.83636
Gene Symbol:	ADRBK1
Sub Type:	Phospho

UniProt Protein Function:	GRK2: a ubiquitous protein kinase of the GRK family. Phosphorylates the beta-2-adrenergic receptor and related G-protein-coupled receptors. Appears to mediate agonist-specific desensitization observed at high agonist concentrations. Expression level is consistently elevated in chronic human heart failure. Mouse models of severe heart failure have been used to demonstrate that inhibition of BARK1 with a peptide inhibitor is sufficient to increase mean survival, reduce dialation and improve cardiac function.
UniProt Protein Details:	Protein type:Kinase, protein; EC 2.7.11.15; Protein kinase, Ser/Thr (non-receptor); Protein kinase, AGC; AGC group; GRK family; BARK subfamily Chromosomal Location of Human Ortholog: 11q13.1 Cellular Component: membrane; cytoplasm; plasma membrane; cytosol Molecular Function:G-protein coupled receptor kinase activity; protein binding; Edg-2 lysophosphatidic acid receptor binding; beta-adrenergic receptor kinase activity; alpha-2A adrenergic receptor binding; ATP binding; protein kinase activity Biological Process: epidermal growth factor receptor signaling pathway; desensitization of G-protein coupled receptor protein signaling pathway; tachykinin signaling pathway; fibroblast growth factor receptor signaling pathway; acetylcholine receptor signaling, muscarinic pathway; nerve growth factor receptor signaling pathway; heart development; peptidyl-threonine phosphorylation; signal transduction; negative regulation of striated muscle contraction; peptidyl-serine phosphorylation; negative regulation of the force of heart contraction by chemical signal; phospholipase C activation; receptor internalization; positive regulation of catecholamine secretion; innate immune response; cardiac muscle contraction
NCBI Summary:	The product of this gene phosphorylates the beta-2-adrenergic receptor and appears to mediate agonist-specific desensitization observed at high agonist concentrations. This protein is an ubiquitous cytosolic enzyme that specifically phosphorylates the activated form of the beta-adrenergic and related G-protein-coupled receptors. Abnormal coupling of beta-adrenergic receptor to G protein is involved in the pathogenesis of the failing heart. [provided by RefSeq, Jul 2008]
UniProt Code:	P25098
NCBI GenInfo Identifier:	126302521
NCBI Gene ID:	156
NCBI Accession:	P25098.2
UniProt Secondary Accession:	P25098,Q13837, Q6GTT3, B0ZBE1,
UniProt Related Accession:	P25098
Molecular Weight:
NCBI Full Name:	Beta-adrenergic receptor kinase 1
NCBI Synonym Full Names:	adrenergic, beta, receptor kinase 1
NCBI Official Symbol:	ADRBK1
NCBI Official Synonym Symbols:	GRK2; BARK1; BETA-ARK1
NCBI Protein Information:	beta-adrenergic receptor kinase 1; beta-ARK-1; G-protein coupled receptor kinase 2
UniProt Protein Name:	Beta-adrenergic receptor kinase 1
UniProt Synonym Protein Names:	G-protein coupled receptor kinase 2
UniProt Gene Name:	ADRBK1
UniProt Entry Name:	ARBK1_HUMAN

Component	Quantity
96-Well Cell Culture Clear-Bottom Microplate	2 plates
10X TBS	24 mL
Quenching Buffer	24 mL
Blocking Buffer	50 mL
15X Wash Buffer	50 mL
Primary Antibody Diluent	12 mL
100x Anti-Phospho Target Antibody	60 µL
100x Anti-Target Antibody	60 µL
Anti-GAPDH Antibody	60 µL
HRP-Conjugated Anti-Rabbit IgG Antibody	12 mL
HRP-Conjugated Anti-Mouse IgG Antibody	12 mL
SDS Solution	12 mL
Stop Solution	24 mL
Ready-to-Use Substrate	12 mL
Crystal Violet Solution	12 mL
Adhesive Plate Seals	2 seals

The following materials and/or equipment are NOT provided in this kit but are necessary to successfully conduct the experiment:

Microplate reader able to measure absorbance at 450 nm and/or 595 nm for Crystal Violet Cell Staining (Optional)
Micropipettes with capability of measuring volumes ranging from 1 µL to 1 ml
37% formaldehyde (Sigma Cat# F-8775) or formaldehyde from other sources
Squirt bottle, manifold dispenser, multichannel pipette reservoir or automated microplate washer
Graph paper or computer software capable of generating or displaying logarithmic functions
Absorbent papers or vacuum aspirator
Test tubes or microfuge tubes capable of storing ≥1 ml
Poly-L-Lysine (Sigma Cat# P4832 for suspension cells)
Orbital shaker (optional)
Deionized or sterile water

*Note: Protocols are specific to each batch/lot. For the correct instructions please follow the protocol included in your kit.

Step	Procedure
1.	Seed 200 µL of 20,000 adherent cells in culture medium in each well of a 96-well plate. The plates included in the kit are sterile and treated for cell culture. For suspension cells and loosely attached cells, coat the plates with 100 µL of 10 µg/ml Poly-L-Lysine (not included) to each well of a 96-well plate for 30 minutes at 37°C prior to adding cells.
2.	Incubate the cells for overnight at 37°C, 5% CO2.
3.	Treat the cells as desired.
4.	Remove the cell culture medium and rinse with 200 µL of 1x TBS, twice.
5.	Fix the cells by incubating with 100 µL of Fixing Solution for 20 minutes at room temperature. The 4% formaldehyde is used for adherent cells and 8% formaldehyde is used for suspension cells and loosely attached cells.
6.	Remove the Fixing Solution and wash the plate 3 times with 200 µL 1x Wash Buffer for five minutes each time with gentle shaking on the orbital shaker. The plate can be stored at 4°C for a week.
7.	Add 100 µL of Quenching Buffer and incubate for 20 minutes at room temperature.
8.	Wash the plate 3 times with 1x Wash Buffer for 5 minutes each time.
9.	Add 200 µL of Blocking Buffer and incubate for 1 hour at room temperature.
10.	Wash 3 times with 200 µL of 1x Wash Buffer for 5 minutes each time.
11.	Add 50 µL of 1x primary antibodies Anti-GRK2 (Phospho-Ser685) Antibody, Anti-GRK2 Antibody and/or Anti-GAPDH Antibody) to the corresponding wells, cover with Parafilm and incubate for 16 hours (overnight) at 4°C. If the target expression is known to be high, incubate for 2 hours at room temperature.
12.	Wash 3 times with 200 µL of 1x Wash Buffer for 5 minutes each time.
13.	Add 50 µL of 1x secondary antibodies (HRP-Conjugated AntiRabbit IgG Antibody or HRP-Conjugated Anti-Mouse IgG Antibody) to corresponding wells and incubate for 1.5 hours at room temperature.
14.	Wash 3 times with 200 µL of 1x Wash Buffer for 5 minutes each time.
15.	Add 50 µL of Ready-to-Use Substrate to each well and incubate for 30 minutes at room temperature in the dark.
16.	Add 50 µL of Stop Solution to each well and read OD at 450 nm immediately using the microplate reader.

(Additional Crystal Violet staining may be performed if desired – details of this may be found in the kit technical manual.)