Work

Rapgef2 Connects GPCR-Mediated cAMP Signals to ERK Activation in Neuronal and Endocrine Cells

Year: 2013

Type: article

Abstract: G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptor (GPCR)-mediated increases in the second messenger cyclic adenosine monophosphate (cAMP) activate the mitogen-activated protein kinase (MAPK) extracellular signal-regulated kinase (ERK), and in neuroendocrine cells, this pathway leads to cAMP-dependent neuritogenesis mediated through Rap1 and B-Raf. We found that the Rap guanine nucleotide exchange factor Rapgef2 was enriched from primary bovine neuroendocrine cells by cAMP-agarose affinity chromatography and that it was specifically eluted by cAMP. With loss-of-function experiments in the rat neuronal cell line Neuroscreen-1 (NS-1) and gain-of-function experiments in human embryonic kidney 293T cells, we demonstrated that Rapgef2 connected GPCR-dependent activation of adenylate cyclase and increased cAMP concentration with the activation of ERK in neurons and endocrine cells. Furthermore, knockdown of Rapgef2 blocked cAMP- and ERK-dependent neuritogenesis. Our data are consistent with a pathway involving the cAMP-mediated activation of Rapgef2, which then stimulates Rap1, leading to increases in B-Raf, MEK, and ERK activity.

Source: Science Signaling

DOI: 10.1126/scisignal.2003993

Authors: Andrew C. Emery, Maribeth V. Eiden, Tomris Mustafa, Lee E. Eiden

Institution: National Institute of Mental Health

Language: English

Topic: Protein Kinase Regulation and GTPase Signaling

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: green

Funders: National Institutes of Health, U.S. Public Health Service, National Institute of Mental Health