Beta 2-Chimaerin from MyBioSource.com

Chimaerins are members of a Rho GTPase-activating proteins (GAPs) that comprises of beta1, alpha1 and alpha 2-chimaerins and the alternatively spliced variants from the beta and alpha-chimaerin genes. These proteins bind to diacylglycerol and phorbol esters like protein kinaseC. They all have a common single C1 domain which is capable of binding phorbol esters and other DAG-mimetics with low nonomolar affinity in the presence of acidic phospholipids. There are two types of chimaerins, alpha2 and beta2 Chimaerins both exhibit an N-terminal SH2 binding domain that interacts with phosphotyrosine containing proteins. The C-terminal chimaerin GTPase activating proteins (GAP)domain is structurally homologus to other Rho and GAP domains such as those found in p190RhoGAP, p50RhoGAP and BCR (1). It is shown that 2-chimaerin accelerates GTP hydrolysis from the small G-protein Rac1, leading to the conversion to the inactive GDP-bound form of Rac (2). Rac1 plays a fundamental role in the control of actin cytoskeleton reorganization, migration, adhesion, transcription, and cell cycle progression (3). An N-terminal SH2 domain in both alpha and beta chimaerins interacts with phosphotyrosine containing proteins while a C-terminalGAP doamain is structurally homologuas to other RhoGAP domains such as those found in other GAP proteins. The beta 2 chimaerins have been shown to accelerate GTP hydrolysis from the small G-protein Rac1 and converts it to inactive GDP bound form. Since Rac1 plays an important role in actin cytoskeletal reorganization, adhesion, migration, transcription and cell cycle progression and chimaerins regulate the activity of Rac1, it is conceivable that chimaerins could play an equally important negatively regulated role in concert with Rac1 responses (4). Chimaerin beta 2 is a 468 amino acid protein (MW 50kDa) protein and chimaerin alpha is a 433 amino acid (45kDa) in size. Chimaerins are expressed in majority of cells and are important regulators of divergence in diacylglycerol (DAG) signaling downstream of tyrosine kinase receptor via a protein kinase C independent mechanisms (1). Beta 2-Chimaerins also undergo phosphorylation to regulate their activity. alpha-chimaerins are alternatively spliced to give two variants (alpha1 and alpha 2-chiamerins), the alpha-1 is a GTPase activating protein for Ras related p21rac while alpha 2-chimaerin exhibted Rac-GAP activity which is stimulated by phosophotidyl serine. Discrete expression of alpha 1-chimaerin and alpha 2-chimerins are seen in brain, alpha 1-chimaerin is expressed in Purkinje cell while both alpha 1 and alpha 2 are expressed in neurons of the cerebral cortex, hippocampus, and thalamus. The alpha 2 variant is expressed only in testis, in early pachytene spermatocytes (4). The chimaerin beta 2-selective antibody was generated against synthetic peptide corresponsing to (163-178) from the human beta chimaerin isoform 2 sequence. This epitope is unique to chimaerin beta 2 only and antibodies to this peptide does not cross react to chimaerin alpha1 or alpha 2 isoforms. The affinity purified antibodies isolated on immobilized antigen based affinity chromatography are stabilized, these antibdoies strongly label a beta 2 chimaerin at 48-50kDa range in western blot positive control samples for chimaerin beta (PC-CHIM2). MyBioSource will also conjugate antibodies with fluorescent probes upon request at extra charge. MyBioSource, provides Western blot positive controls for beta 2-chimaerin in ready-to-use buffer for easy identification of target protein. Limited quantities of antigenic blocking peptide is also available. Please enquire for their availability before ordering