Calcium singling genes are critical for growth, development and circadian clock in Neurospora crassa

We found that the calcium (Ca²⁺) signaling genes cna-1, cnb-1, ncs-1, plc-1, splA2, cpe-1, cam, camk-1, and camk-2 are critical for the growth and development in the model filamentous fungus Neurospora crassa. The cna-1 and cnb-1 genes encodes the calcineurin catalytic and the regulatory subunits, respectively, and we isolated their dominant negative mutants that affected growth and circadian rhythm in N. crassa. Additionally, we found that the calcineurin interacts with the calmodulin (CaM), and transcription factor CRZ-1. The CRZ-1 is localized in nucleus after its dephosphorylation by the calcineurin to upregulate the expression of ncs-1 in response to Ca²⁺ stress. We propose a model that the calcineurin dephosphorylates CRZ-1 promoting its nuclear localization to upregulate the NCS-1 expression for survival under cellular stress condition. Thus, we showed that the Ca²⁺ signaling genes play a critical role in regulating growth, development, and circadian clock in N. crassa.