PI3P-dependent RAC exchanger protein 1

Accession #/Synonym:  Q8TCU6;

PRex1 is a leukocyte specific Rho/RAC family of GTPase exchange factor. The P-Rex family comprises P-Rex1, P-Rex2, and P-Rex2b.  P-REX1 GEF activity is critical for RAC-mediated formation of reactive oxygen species in response to PIP3 and Gβγ signaling in neutrophils. P-REX1 expression is increased in metastatic prostate cancers and has been shown to mediate a RAC dependent metastatic and invasive phenotype in prostate cancer cell lines. P-Rex family Rac GEFs are expressed at high levels in cerebellar Purkinje neurons. P-Rex is activated by PtdIns(3,4,5)P₃,reaction catalysed by PI3K, which is essential for expression of hippocampal LTP and for the NMDA-evoked exocytosis of GluR1-containing AMPARs in cultured hippocampal neurons. P-Rex loss is also associated with changes in Purkinje neuron dendrite morphology, implicating it in structural changes in these postsynaptic compartments (1). P-REX2a is a guanine nucleotide exchange factor (GEF) for the RAC-GTPase which has sequence similarity to the leukocyte-specific RAC GEF, P-REX1.  P-REX2a is a widely expressed paralog of P-REX1 and contains an N-terminal Dbl homology and pleckstrin homology (DHPH) domain [which confers GEF activity], pairs of PDZ and DEP domains, and a C-terminus with weak similarity to inositol 4-polyphosphate phosphatase. The P-REX2a gene is located on chromosome 8q13, a region of frequent amplification in breast, prostate, and colorectal cancers which is also linked to aggressive cancer phenotypes and metastatic progression.(2).

P-Rex family of Rac-GEFs are synergistically activated by the βγ-subunits of heterotrimeric G proteins and by the PI3P that is generated by phosphoinositide-3-kinase (PI3K). P-Rex1 is expressed in white blood cells and brain, P-Rex2 more widely but not in leukocytes, and P-Rex2b, only in the heart. P-Rex1 regulates GPCR-dependent Rac2 activation, reactive oxygen species (ROS) production, and chemotaxis in neutrophils, and neutrophil recruitment to inflammatory sites. P-Rex1 controls neurotrophin-stimulated cell migration (3)
The P-Rex-selective antibodies were generated against peptide taken form the region spanning 800-860 amino acids of Prex1 gene.  The 21mer Prex peptide antibodies are affinity purified on immobilized antigen based affinity chromatography. Prex affinity purified antibodies are stabilized in antibody stabilization buffer for long-term storage.  FabGennix will conjugate P-Rex antibodies to fluorophores and secondary enzymes (horseradish peroxidase and alkaline phosphatase) upon request at nominal cost.  FabGennix will also provide limited quantities of antigenic blocking peptide and western blot positive control in ready-to-use buffer for P-Rex (please inquire availability before ordering).  FabGennix has made a number of new antibodies in signal transduction research area, for a complete listing please visit www.FabGenni.com.

Immunogen:        Synthetic peptide corresponding to amino acid 815-836 of PI3P dependent Rac-exchangeer 1 protein corresponding to amino acids (qee dqa dsa fpl lsl gpr lsl c).  The peptide was post synthetically modified and conjugated to KLH using hetero-bifunctional cross linker for immunization of rabbits. 

Concentration:     The Prex-101AP and Prex-FITC antibody concentrations are 0.5-0.65mg/ml in antibody stabilization buffer.

Applications:        ELISA/dot blot:  Antibody dilution 1:20,000-1:50,000;.  Western blot:  Antibody dilution 1:500-750 in diluObuffer for use with PC-Prex sample (15ul/lane).  Other applications (IHC, confocal and Immunoprecipitation for these antibodies is not established.  Use of this antibody in applications not listed here does not necessarily exclude its use in such procedures. Investigators employing this antibody in applications not listed here may request a complimentary sample. Trex-101AP labels a diffuse band at 205-210kDa in PC-Prex sample. 

Protocols:         Standard protocol for various applications (WB; IMM and IHC) of this antibody can be requested by calling Technical service line, basic information on this antibody is provided with the product specification sheet, however, FabGennix Inc. recommends investigators to optimize conditions for use of this antibody in their assay.

Form/Storage:  The antiserum is supplied in antibody stabilization buffer with preservatives.  For long-term storage of antibody, store at -20^oC FabGennix Inc. does not recommend storage of very dilute antibody solutions unless they are prepared in specially formulated multi-use antibody dilution buffer (Cat # DiluOBuffer).  Working solutions of antibodies in DiluOBuffer should be filtered through 0.45ƒÝ filter after every use for long-term storage.

 

For research use only, not for diagnostic or therapeutic use.