Ras-specific Guanine Nucleotide exchange Releasing Factor 2 from MyBioSource.com

Guanine nucleotide Exchange Factors (GEFs) are proteins involved in the activation of small GTPases which act as molecular switches in intracellular signaling pathways and have many downstream targets. Ras-specific Guanine nucleotide releasing factor (RASGRF) belongs to a family of GEFs that activate Ras proteins in cells by calcium/calmodulin binding and by phosphorylation. Ras-GRF proteins are expressed primarily on neurons of the central nervous system and they stimulate the conversion of the GDP-bound form into the active form, thus RAS-specific GTPases cycle between an inactive GDP-bound state and an active GTP-bound state (1). A critical step in signal transduction, responses to stimulation of cell surface receptors by their ligands, involve the accumulation of Ras proteins in their active GTP-bound state. To reach their active GTP-bound state, Ras proteins first release bound GDP, a rate limiting step mediated by a guanine nucleotide releasing factor (GRF) (2).The Ras GRF family exchange factors, both endogenous and ectopically expressed, are present in the endoplasmic reticulum but not in the Golgi complex. The mammalian Ras p21 GRF protein has been designated Ras-GRF1 p140. Ras-GRF1 accelerates release of GDP from H- and N-Ras p21 protein in vitro, but not from the related Ral A or Cdc42Hs GTP-binding proteins. Ras-GRF2 p135 is highly homologous to Ras-GRF1 p140 except in the region between the REM and CDC25 domains and appears to function similarly to Ras-GRF1 p140.

GRF2 is a human GRF protein for Ras protein. It belongs to the adaptor-type Src homology (SH) 2-containing molecules. Src homology 2 domains are globular protein modules present in a large variety of functionally distinct proteins. They mediate binding events that control the activity and localization of many proteins involved in the transmission of signals from the cell surface to the nucleus. The mRNAs of these proteins are expressed ubiquitously in human adult and fetal tissues. Ras-GRF1 (GRF1) and Ras-GRF2 (GRF2) constitute a family of similar calcium sensors that regulate synaptic plasticity. They are both GRF that contain a very similar set of functional domains, including N-terminal pleckstrin homology, coiled-coil, and calmodulin-binding IQ domains and C-terminal Dbl homology Rac-activating domains, Ras-exchange motifs, and CDC25 Ras-activating domains. GRF-1 is primarily brain specific and induces the release of bound GDP from Ras which allows the binding of GTP. GRF-2 has similar functions compared to GRF-1 and displays exchange activity towards Rac (3).

RASGRF2-selective antibodies were generated against peptides taken from the human RASGRF2 protein. The RASGRF2 selective antibodies are affinity purified on an immobilized antigen based affinity matrix, the isolated antibodies were then stabilized in antibody stabilization buffer for long-term storage. The RASGRF2-selective antibodies are fully characterized for applications in western blotting and ELISA at the recommended dilutions