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To Purchase # 8819S

8819S 1 Kit (30 rxns)

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Product Includes Quantity Storage Temp
GST-Human PAK1-PBD 600 µg -20°C
Cdc42 Mouse mAb 300 µl -20°C
GDP 50 µl -80°C
GTP γS 50 µl -80°C
Glutathione Resin 3 ml 4°C
SDS Sample Buffer 1.5 ml 4°C
Lysis/Binding/Wash Buffer 100 ml 4°C
Spin Cup and Collection Tubes 30 Ea 4°C

Product Description

The Active Cdc42 Detection Kit provides all reagents necessary for measuring activation of Cdc42 GTPase in the cell. GST-PAK1-PBD fusion protein is used to bind the activated form of GTP-bound Cdc42, which can then be immunoprecipitated with glutathione resin. Cdc42 activation levels are then determined by western blot using a Cdc42 Mouse mAb.


Specificity / Sensitivity

Active Cdc42 Detection Kit detects endogenous levels of GTP-bound (active) Cdc42 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

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, 1301-1312.

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.



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