The Surface Cyclic AMP Receptors, CAR1, CAR2, and CAR3, Promote Ca2+ Influx in Dictyostelium Discoideum by a G Alpha 2-independent Mechanism
Overview
Molecular Biology
Authors
Affiliations
Activation of surface folate receptors or cyclic AMP (cAMP) receptor (cAR) 1 in Dictyostelium triggers within 5-10 s an influx of extracellular Ca2+ that continues for 20 s. To further characterize the receptor-mediated Ca2+ entry, we analyzed 45Ca2+ uptake in amoebas overexpressing cAR2 or cAR3, cARs present during multicellular development. Both receptors induced a cAMP-dependent Ca2+ uptake that had comparable kinetics, ion selectivity, and inhibitor profiles as folate- and cAR1-mediated Ca2+ uptake. Analysis of mutants indicated that receptor-induced Ca2+ entry does not require G protein alpha subunits G alpha 1, G alpha 2, G alpha 3, G alpha 4, G alpha 7, or G alpha 8. Overexpression of cAR1 or cAR3 in g alpha 2- cells did not restore certain G alpha 2-dependent events, such as aggregation, or cAMP-mediated activation of adenylate and guanylate cyclases, but these strains displayed a cAMP-mediated Ca2+ influx with kinetics comparable to wild-type aggregation-competent cells. These results suggest that a plasma membrane-associated Ca(2+)-influx system may be activated by at least four distinct chemoreceptors during Dictyostelium development and that the response may be independent of G proteins.
Ion Signaling in Cell Motility and Development in .
Morimoto Y Biomolecules. 2024; 14(7).
PMID: 39062545 PMC: 11274586. DOI: 10.3390/biom14070830.
Different Heterotrimeric G Protein Dynamics for Wide-Range Chemotaxis in Eukaryotic Cells.
Kamimura Y, Ueda M Front Cell Dev Biol. 2021; 9:724797.
PMID: 34414196 PMC: 8369479. DOI: 10.3389/fcell.2021.724797.
A polycystin-type transient receptor potential (Trp) channel that is activated by ATP.
Traynor D, Kay R Biol Open. 2016; 6(2):200-209.
PMID: 28011630 PMC: 5312093. DOI: 10.1242/bio.020685.
Liao X, Buggey J, Lee Y, Kimmel A Mol Biol Cell. 2013; 24(13):2146-55.
PMID: 23657816 PMC: 3694798. DOI: 10.1091/mbc.E13-03-0130.
Kataria R, Xu X, Fusetti F, Keizer-Gunnink I, Jin T, van Haastert P Proc Natl Acad Sci U S A. 2013; 110(16):6424-9.
PMID: 23576747 PMC: 3631646. DOI: 10.1073/pnas.1301851110.