RAPGEF4 antibody

Background of RAPGEF4 antibody

General secondary messenger cAMP levels are altered by many extracellular physiological signals including neurotransmitters, immunomodulators and hormones via the activation of G-protein coupled receptor (GPCR) activation. Activation of GPCRs by ligand interaction stimulates the heterotrimeric G-proteins thereby increasing the activity of one or more subtypes of adenylate cyclases to increase the formation of cAMP. The increased intracellular levels of cAMP transduce the signal transduction via protein kinase A and via small GTPase, RAP 1 (1,2). The activation of RaP1 by cAMP is independent f PKA and is mediated by recently discovered family of guanine nucleotide exchange factors (GEFs) called cAMP-GEFs or Epacs. The Epac signaling therefore represent a novel mechanism for cAMP signaling with in the cAMP cascade.
There are 2 members of the Epac family, Epac1 and Epac 2. Both proteins are multidomain proteins containing an autoinhibitory cAMP-binding domain that inhibits the catalytic region and a DEP domain (dishevelled, Egl-10 and pleckstrin homology domain) targeting the membrane anchors (3). EPAC2 has an additional cAMP-binding site in its N-terminus that binds cAMP with low affinity [2]. EPAC1 mRNA is broadly expressed, with particularly high levels occurring in the thyroid, ovary, kidney and certain brain regions, whereas expression of EPAC2 mRNA appears to be restricted to the brain and adrenal glands (4, 5). Epac 1 and Epac 2 also interact with light chain 2 (LC2) or MAP1A that serves as a scaffolding structure to stabilize the signal transduction complex (6).