Cell Signaling Technology

Product Pathways - HTScan Kinase Assay Kits

HTScan® PKCι Kinase Assay Kit #7598

Cell Signaling Technology offers a full line of protein kinases, substrates, antibody detection reagents and HTScan® kits. Browse our "Reagents for High-Throughput Screening" product listing or contact us at drugdiscovery@cellsignal.com.

Kit Includes Quantity
Phospho-PKA Substrate (RRXS/T) (100G7E) Rabbit mAb # 9624 30 microliters
CREB (Ser133) Biotinylated Peptide # 1331 1.25 milliliters
PKCι Kinase # 7599 5 micrograms
ATP (10 mM) # 9804 1 milliliters
Kinase Buffer (10X) # 9802 15 milliliters

Description

The kit provides a means of performing kinase activity assays with recombinant human PKCiota kinase. It includes active PKCiota kinase (supplied as a GST fusion protein), a biotinylated peptide substrate and a phospho-serine/threonine antibody for detection of the phosphorylated form of the substrate peptide.

Molecular Weights

Biotin-peptide: 2,326 Daltons. GST-PKCiota Kinase: 97 kDa.

Peptide Core Sequence

RRPS*YRK

Kinase Assay - Radiometric

Kinase Assay - Radiometric

Figure 1. PKCiota kinase activity was measured in a radiometric assay using the following reaction conditions: 60 mM HEPES-NaOH, pH 7.5, 5 mM MgCl2, 1.32 mM CaCl2, 1 mM EDTA, 1.25 mM EGTA, 0.25 µg/50 µl phosphatidylserine, 50 ng/50 µl 1.2 Dioleyl-glycerol, 1.2 mM DTT, ATP: variable , 2.5 µg/50 µl PEG20,000, Substrate: PKC(19-31) (RFARKGSLRQKNV), 0.5µg/50 µl and Recombinant PKCiota: 50 ng/50 µl.

Kinase Assay - DELFIA

Kinase Assay - DELFIA

Figure 3. Dose dependence curve of PKCiota kinase activity: DELFIA® data generated using Phospho-PKA Substrate (RRXS/T) (100G7) Rabbit mAb #9624 to detect phosphorylation of substrate peptide (#1331) by PKCiota kinase. In a 50 µl reaction, increasing amounts of PKCiota and 1.5 µM substrate peptide were used per reaction at room temperature for 30 minutes. (DELFIA® is a registered trademark of PerkinElmer, Inc.)

Kinase Assay - DELFIA

Kinase Assay - DELFIA

Figure 5. Staurosporine inhibition of PKCiota kinase activity: DELFIA® data generated using Phospho-PKA Substrate (RRXS/T) (100G7) Rabbit mAb #9624 to detect phosphorylation of PKCiota substrate peptide (#1331) by PKCiota kinase. In a 50 µl reaction, 50 ng PKCiota, 1.5 µM substrate peptide, 20 µM ATP and increasing amounts of staurosporine were used per reaction at room temperature for 30 minutes. (DELFIA® is a registered trademark of PerkinElmer, Inc.)


Kinase Assay - DELFIA

Kinase Assay - DELFIA

Figure 4. Peptide concentration dependence of PKCiota kinase activity: DELFIA® data generated using Phospho-PKA Substrate (RRXS/T) (100G7) Rabbit mAb #9624 to detect phosphorylation of substrate peptide (#1331) by PKCiota kinase. In a 50 µl reaction, 50 ng of PKCiota and increasing concentrations of substrate peptide were used per reaction at room temperature for 30 minutes. (DELFIA® is a registered trademark of PerkinElmer, Inc.)

Kinase Assay - DELFIA

Kinase Assay - DELFIA

Figure 2. Time course of PKCiota kinase activity: DELFIA® data generated using Phospho-PKA Substrate (RRXS/T) (100G7) Rabbit mAb #9624 to detect phosphorylation of PKCiota substrate peptide (#1331) by PKCiota kinase. In a 50 µl reaction, 50 ng PKCiota and 1.5 uM substrate peptide were used per reaction. (DELFIA® is a registered trademark of PerkinElmer, Inc.)

Source / Purification

The GST-Kinase fusion protein was produced using a baculovirus expression system with a construct expressing full length human PKCiota (Met1-Val587) (GenBank Accession No. NM_002740) with an amino-terminal GST tag. The protein was purified by one-step affinity chromatography using glutathione-agarose.

Quality Control

The substrate peptide was selected using our Serine/Threonine Kinase Substrate Screening Kit #7400. Phospho-PKA Substrate (RRXS/T) (100G7) Rabbit mAb #9624 was used for detection. The quality of the biotinylated peptide was evaluated by reverse-phase HPLC and by mass spectrometry.Purified PKCiota kinase was quality controlled for purity by SDS-PAGE followed by Coomassie stain and Western blot. PKCiota kinase activity was determined using a radiometric filter binding assay [Fig.1]. Time course [Fig.2], kinase dose dependency [Fig.3] and substrate dose-dependency [Fig.4] assays were performed to verify PKCiota activity using the PKCiota substrate peptide provided in this kit. PKCiota sensitivity to the inhibitor staurosporine was measured using the PKCiota substrate peptide provided in this kit [Fig.5].

Background

Activation of protein kinase C (PKC) is one of the earliest events in a cascade that controls a variety of cellular responses, including secretion, gene expression, proliferation and muscle contraction (1,2). PKC isoforms belong to three groups based on calcium dependency and activators. Classical PKCs are calcium-dependent via their C2 domains and are activated by phosphatidylserine (PS), diacylglycerol (DAG) and phorbol esters (TPA, PMA) through their cysteine-rich C1 domains. Both novel and atypical PKCs are calcium-independent, but only novel PKCs are activated by PS, DAG and phorbol esters (3-5). Members of these three PKC groups contain a pseudo-substrate or autoinhibitory domain that binds to substrate-binding site in the catalytic domain to prevent activation in the absence of cofactors or activators.Control of PKC activity is regulated through three distinct phosphorylation events. Phosphorylation of Thr500 in the activation loop, the autophosphorylation site at Thr641 and at carboxy-terminal hydrophobic site Ser660 occurs in vivo (2). Atypical PKC isoforms lack hydrophobic region phosphorylation, which correlates with the presence of glutamic acid rather than the serine or threonine residues found in more typical PKC isoforms. Either the enzyme PDK1 or a close relative is responsible for PKC activation.A recent addition to the PKC superfamily is PKCμ (PKD), which is regulated by DAG and TPA through its C1 domain. PKD is distinguished by the presence of a PH domain and by its unique substrate recognition and Golgi localization (6). PKC-related kinases (PRK) lack the C1 domain and do not respond to DAG or phorbol esters. Phosphatidylinositol lipids activate PRKs and small Rho-family GTPases bind to the homology region 1 (HR1) to regulate PRK kinase activity (7).

PKCiota has been suggested to mediate signaling pathways supporting cell proliferation, differentiation, and survival in response to growth factors and nutrients. PKCiota also plays a critical role in cell-cell adhesion, cell polarization process, and tight junction formation in epithelial cells (10, 11).

  1. Nishizuka, Y. (1984) Nature 308, 693-698.
  2. Keranen, L.M. et al. (1995) Curr. Biol. 5, 1394-1403.
  3. Mellor, H. and Parker, P.J. (1998) Biochem J. 332 (Pt 2), 281-292.
  4. Ron, D. and Kazanietz, M.G. (1999) FASEB J. 13, 1658-1676.
  5. Moscat, J. and Diaz-Meco, M.T. (2000) EMBO Rep. 1, 399-403.
  6. Baron, C.L. and Malhotra, V. (2002) Science 295, 325-328.
  7. Flynn, P. et al. (2000) J. Biol. Chem. 275, 11064-11070.
  8. Suzuki, A. et al. (2003) J Biochem (Tokyo) 133, 9-16.
  9. Mackay, H.J. and Twelves, C.J. (2003) Endocr Relat Cancer 10, 389-96.

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This product is for in vitro research use only and is not intended for use in humans or animals. This product is not intended for use as therapeutic or in diagnostic procedures.

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