Related Experiment Video
Updated: Jun 17, 2026

Imaging G-protein Coupled Receptor (GPCR)-mediated Signaling Events that Control Chemotaxis of Dictyostelium Discoideum
Published on: September 20, 2011
MAP kinases have different functions in Dictyostelium G protein-mediated signaling
Hoai-Nghia Nguyen1, Brent Raisley, Jeffrey A Hadwiger
1Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, 74078-3020, USA.
Abstract:
Extracellular signal regulated kinases (ERKs) are a class of MAP kinases that function in many signaling pathways in eukaryotic cells and in some cases, a single stimulus can activate more than one ERK suggesting functional redundancy or divergence from a common pathway. Dictyostelium discoideum encodes only two MAP kinases, ERK1 and ERK2, that both function during the developmental life cycle. To determine if ERK1 and ERK2 have overlapping functions, chemotactic and developmental phenotypes of erk1(-) and erk2(-) mutants were assessed with respect to G protein-mediated signal transduction pathways. ERK1 was specifically required for Galpha5-mediated tip morphogenesis and inhibition of folate chemotaxis but not for cAMP-stimulated chemotaxis or cGMP accumulation. ERK2 was the primary MAPK phosphorylated in response to folate or cAMP stimulation. Cell growth was not altered in erk1(-), erk2(-) or erk1(-)erk2(-) mutants but each mutant displayed a different pattern of cell sorting in chimeric aggregates. The distribution of GFP-ERK1 or GFP-ERK2 fusion proteins in the cytoplasm and nucleus was not grossly altered in cells stimulated with cAMP or folate. These results suggest ERK1 and ERK2 have different roles in G protein-mediated signaling during growth and development.
More Related Videos
Related Concept Videos
MAPK Signaling Cascades
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
Amplifying Signals via Enzymatic Cascade
Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Activation and Inactivation of G Proteins
Amplifying Signals via Second Messengers

