A cyanobacterial light activated adenylyl cyclase partially restores development of a Dictyostelium discoideum, adenylyl cyclase a null mutant

A light-regulated adenylyl cyclase, mPAC, was previously identified from the cyanobacterium Microcoleuschthonoplastes PCC7420. MPAC consists of a flavin-based blue light-sensing LOV domain and a catalyticdomain. In this work, we expressed mPAC in an adenylate cyclase A null mutant (aca−) of the eukaryoteDictyostelium discoideum and tested to what extent light activation of mPAC could restore the cAMP-dependent developmental programme of this organism. Amoebas of Dictyostelium, a well-establishedmodel organism, generate and respond to cAMP pulses, which cause them to aggregate and constructfruiting bodies. mPAC was expressed under control of a constitutive actin-15 promoter in D. discoideumand displayed low basal adenylyl cyclase activity in darkness that was about five-fold stimulated byblue light. mPAC expression in aca− cells marginally restored aggregation and fruiting body formationin darkness. However, more and larger fruiting bodies were formed when mPAC expressing cells wereincubated in light. Extending former applications of light-regulated AC, these results demonstrate thatmPAC can be used to manipulate multicellular development in eukaryotes in a light dependent manner.