Ca2+ signalling is not required for chemotaxis in Dictyostelium

被引:91
作者
Traynor, D
Milne, JLS
Insall, RH
Kay, RR
机构
[1] MRC, Mol Biol Lab, Cambridge CB2 2QH, England
[2] Univ Birmingham, Sch Biosci, Birmingham B15 2TT, W Midlands, England
关键词
calcium signalling; chemotaxis; cyclic-AMP; Dictyostelium; InsP(3) receptor;
D O I
10.1093/emboj/19.17.4846
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Dictyostelium cells can move rapidly towards a source of cyclic-AMP (cAMP), This chemoattractant is detected by G-protein-linked receptors, which trigger a signalling cascade including a rapid influx of Ca2+. We have disrupted an inositol 1,4,5-trisphosphate (InsP(3)) receptor-like gene, iplA, to produce null cells in which Ca2+ entry in response to chemoattractants is abolished, as is the normal increase in free cytosolic Ca2+ ([Ca2+](c)) that follows chemotactic stimulation. However, the resting [Ca2+](c) is similar to wild type. This mutant provides a test for the role of Ca2+ influx in both chemotaxis and the signalling cascade that controls it. The production of cyclic-GMP and cAMP, and the activation of the MAP kinase, DdERK2, triggered from the cAMP receptor, are little perturbed in the mutant; mobilization of actin into the cytoskeleton also follows similar kinetics to wild type, Mutant cells chemotax efficiently towards cAMP or folic acid and their sensitivity to cAMP is similar to wild type, Finally, they move at similar speeds to wild-type cells, with or without chemoattractant, We conclude that Ca2+ signalling is not necessary for chemotaxis to cAMP.
引用
收藏
页码:4846 / 4854
页数:9
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