Revision 4

#8815Store at -80C, -20C, 4C

Cell Signaling Technology

Orders: 877-616-CELL (2355) [email protected]

Support: 877-678-TECH (8324)

Web: [email protected] cellsignal.com

3 Trask LaneDanversMassachusetts01923USA
For Research Use Only. Not for Use in Diagnostic Procedures.
:

:

:

:

UniProt ID:

#P63000

Entrez-Gene Id:

5879

Product Information

Storage

GTPγS: Store at -80°C
GDP: Store at -80°C
GST-Human PAK1-PBD: Store at -20°C
Rac1 Mouse mAb: Store at -20°C
Lysis/Binding/Wash Buffer: Store at 4°C
Glutathione Resin: Store at 4°C
SDS Sample Buffer: Store at 4°C
Spin Cup and Collection Tubes: Store at RT

Specificity / Sensitivity

Active Rac1 Detection Kit detects endogenous levels of GTP-bound (active) Rac1 as shown in Figure 1. This kit detects proteins from the indicated species, as determined through in-house testing, but may also detect homologous proteins from other species.

Species Reactivity:

Human, Mouse

Product Description

The Active Rac1 Detection Kit provides all reagents necessary for measuring activation of Rac1 GTPase in the cell. GST-PAK1-PBD fusion protein is used to bind the activated form of GTP-bound Rac1, which can then be immunoprecipitated with glutathione resin. Rac1 activation levels are then determined by western blot using a Rac1 Mouse mAb.

Background

The Ras superfamily of small GTP-binding proteins (G proteins) comprise a large class of proteins (over 150 members) that can be classified into at least five families based on their sequence and functional similarities: Ras, Rho, Rab, Arf, and Ran (1-3). These small G proteins have both GDP/GTP-binding and GTPase activities and function as binary switches in diverse cellular and developmental events that include cell cycle progression, cell survival, actin cytoskeletal organization, cell polarity and movement, and vesicular and nuclear transport (1). An upstream signal stimulates the dissociation of GDP from the GDP-bound form (inactive), which leads to the binding of GTP and formation of the GTP-bound form (active). The activated G protein then goes through a conformational change in its downstream effector-binding region, leading to the binding and regulation of downstream effectors. This activation can be switched off by the intrinsic GTPase activity, which hydrolyzes GTP to GDP and releases the downstream effectors. These intrinsic guanine nucleotide exchange and GTP hydrolysis activities of Ras superfamily proteins are also regulated by guanine nucleotide exchange factors (GEFs) that promote formation of the active GTP-bound form and GTPase activating proteins (GAPs) that return the GTPase to its GDP-bound inactive form (4).
Rac and Cdc42 are members of the Rho-GTPase family. In mammals, Rac exists as three isoforms, Rac1, Rac2, and Rac3, which are highly similar in sequence. Rac1 and Cdc42, the most widely studied of this group, are ubiquitously expressed. Rac2 is expressed in cells of hematopoietic origin, and Rac3, while highly expressed in brain, is also found in many other tissues. Rac and Cdc42 play key signaling roles in cytoskeletal reorganization, membrane trafficking, transcriptional regulation, cell growth, and development (5). GTP binding stimulates the activity of Rac/Cdc42, and the hydrolysis of GTP to GDP through the protein's intrinsic GTPase activity, rendering it inactive. GTP hydrolysis is aided by GTPase activating proteins (GAPs), while exchange of GDP for GTP is facilitated by guanine nucleotide exchange factors (GEFs). Another level of regulation is achieved through the binding of RhoGDI, a guanine nucleotide dissociation inhibitor, which retains Rho family GTPases, including Rac and Cdc42, in their inactive GDP-bound state (6,7).

  1. Takai, Y. et al. (2001) Physiol Rev 81, 153-208.
  2. Colicelli, J. (2004) Sci STKE 2004, RE13.
  3. Wennerberg, K. et al. (2005) J Cell Sci 118, 843-6.
  4. Vigil, D. et al. (2010) Nat Rev Cancer 10, 842-57.
  5. Wennerberg, K. and Der, C.J. (2004) J Cell Sci 117, 1301-12.
  6. Bernards, A. and Settleman, J. (2004) Trends Cell Biol 14, 377-85.
  7. Rossman, K.L. et al. (2005) Nat Rev Mol Cell Biol 6, 167-80.

Species Reactivity

Species reactivity is determined by testing in at least one approved application (e.g., western blot).

Cross-Reactivity Key

H: human M: mouse R: rat Hm: hamster Mk: monkey Vir: virus Mi: mink C: chicken Dm: D. melanogaster X: Xenopus Z: zebrafish B: bovine Dg: dog Pg: pig Sc: S. cerevisiae Ce: C. elegans Hr: horse GP: Guinea Pig Rab: rabbit All: all species expected

Trademarks and Patents

Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.
All other trademarks are the property of their respective owners. Visit cellsignal.com/trademarks for more information.

Limited Uses

Except as otherwise expressly agreed in a writing signed by a legally authorized representative of CST, the following terms apply to Products provided by CST, its affiliates or its distributors. Any Customer's terms and conditions that are in addition to, or different from, those contained herein, unless separately accepted in writing by a legally authorized representative of CST, are rejected and are of no force or effect.

Products are labeled with For Research Use Only or a similar labeling statement and have not been approved, cleared, or licensed by the FDA or other regulatory foreign or domestic entity, for any purpose. Customer shall not use any Product for any diagnostic or therapeutic purpose, or otherwise in any manner that conflicts with its labeling statement. Products sold or licensed by CST are provided for Customer as the end-user and solely for research and development uses. Any use of Product for diagnostic, prophylactic or therapeutic purposes, or any purchase of Product for resale (alone or as a component) or other commercial purpose, requires a separate license from CST. Customer shall (a) not sell, license, loan, donate or otherwise transfer or make available any Product to any third party, whether alone or in combination with other materials, or use the Products to manufacture any commercial products, (b) not copy, modify, reverse engineer, decompile, disassemble or otherwise attempt to discover the underlying structure or technology of the Products, or use the Products for the purpose of developing any products or services that would compete with CST products or services, (c) not alter or remove from the Products any trademarks, trade names, logos, patent or copyright notices or markings, (d) use the Products solely in accordance with CST Product Terms of Sale and any applicable documentation, and (e) comply with any license, terms of service or similar agreement with respect to any third party products or services used by Customer in connection with the Products.

Revision 4
#8815

Active Rac1 Detection Kit

Active Rac1 Detection Kit: Image 1 Expand Image
Figure 2. The GTP-bound GTPase pull-down process can be divided into 3 steps as shown. Step 1: Mix sample, binding protein, and glutathione resin in the spin cup and incubate at 4ºC to allow GTP-bound GTPase binding to the glutathione resin through GST-linked binding protein. Step 2: Remove unbound proteins by centrifugation. Step 3: Elute glutathione resin-bound GTPase with SDS buffer. The eluted sample can then be analyzed by western blot.
Active Rac1 Detection Kit: Image 2 Expand Image
Figure 1. NIH/3T3 cell lysates (500 µl at 1 mg/ml) were treated in vitro with GTPγS or GDP to activate or inactivate Rac1 (refer to optional step C in protocol). The lysates were then incubated with glutathione resin and GST-PAK1-PBD (lanes 2 and 3). GTPγS-treated lysate was also incubated without GST-PAK1-PBD in the presence of glutathione resin as a negative control (lane 4). Western blot analysis of cell lysate (20 µg, lane 1) or 20 µl of the eluted samples (lanes 2, 3, and 4) was performed using a Rac1 Mouse mAb. Anti-mouse IgG, HRP-linked Antibody #7076 was used as the secondary antibody.